Laminated bus bar for use with a power conversion configuration

ABSTRACT

An apparatus for linking together power switching devices having intra-converter connection terminals to form a power conversion assembly, the apparatus comprising a planar bus bar including positive and negative DC bus layers and insulating layers that insulate each of the DC bus layers, the bar also including at least a first external insulating layer that forms a first external surface of the bar, the bar also forming at least first and second linking edges and first and second pluralities of linkages formed along the first and second linking edges, respectively, each linkage linked to one of the positive and negative DC bus layers and configured to be linkable to at least one of the power switching device intra-converter connection terminals, in some cases positive and negative DC bus linkages are also provided to render the conversion assembly extremely versatile.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

BACKGROUND OF THE INVENTION

[0003] The field of the invention is power converters and morespecifically converter configurations including heat sinks that reducethe overall space required to accommodate the configurations.

[0004] It is well known that variable speed drives of the type used tocontrol industrial electric motors include numerous electroniccomponents. Among the various electronic components used in typicalvariable-speed drives, all generate heat to a varying degree duringoperation. Typically, high-power switching devices such as IGBTs,diodes, SCRs and the like as well as storage devices such as capacitorsare responsible for generating most of the heat in a variable-speeddrive. It is for this reason, therefore, that most variable-speed drivesinclude a heat sink(s) upon which the power switching devices aremounted. The heat sink(s) conducts potentially damaging heat fromassembly components.

[0005] Selecting the size and design of a heat sink for a particularvariable speed drive is somewhat of a challenge. First, a designer mustbe aware of the overall characteristics of the motor and drive pair.Second, the designer must understand the industrial application in whichthe motor and drive pair will be used, including the continuous and peakdemands that will likely be placed on the motor and drive by the load.Third, the designer must accommodate, in the design, certain unexpectedconditions that would deleteriously affect the heat transfer capabilityof the heat sink such as unexpectedly high ambient temperatures,physical damage to the heat sink such as mechanical damage, or a buildup of a debris layer, as examples. Fourth, the heat sink(s) must bephysically dimensioned so as to fit into the space allotted per customerrequirements, cabinet or enclosure size, or the like.

[0006] In the past, air-cooled heat conducting plates were used totransfer thermal energy from electronic parts to the ambient air. Thesewere passive heat-transfer devices and were generally formed of alight-weight aluminum extrusion including a set of fins. As a generalrule, heat transfer effectiveness is based on the temperaturedifferential between the power devices and the ambient air temperature.Of course, in order to provide adequate heat conduction, heat sinks ofthis type oftentimes are necessarily large and, therefore, bulky andexpensive. If high ambient conditions exist, the heat sink becomesineffective or useless as heat removal cannot be accomplished regardlessof the size of the heat sink. If the variable speed drive was in anenclosed space the heat removed from the drive would need to beexhausted or conditioned for recirculation.

[0007] By forcing air over fins defined on the heat-conducting plate(e.g., an aluminum extrusion), improved cooling efficiency can berealized. Large blower motors are often used for this purpose. However,as the fins defined in the aluminum extrusions become dirty or corrodedduring use, the heat sinks become less effective or useless altogether.Blower motors cannot be used in environments where air cleanliness wouldclog filtration. Therefore, air conditioning equipment is often added tointernally circulate and cool the air that is passed over the heat sinkfins.

[0008] Liquid cooled heat sinks or cold plates have also been used forsome applications but with limited success. Generally, a liquid cooledheat sink includes a series of chambers or channels that are formedinternally within a sink body member that is formed of material (e.g.,copper or aluminum) that readily conducts heat. The body member includesat least one mounting surface for receiving heat generating devices. Thechannels are typically configured so that at least one channel sectionis formed adjacent each surface segment to which a heat generatingdevice is mounted—typical channel configurations are serpentine. Acoolant liquid is pumped through the channels from one or more inletports to one or more outlet ports to cool the sink member and henceconduct heat away form the heat generating devices.

[0009] The industry has developed several ways in which to manufactureliquid cooled heat sinks and, each of the different ways to manufacturehas different costs associated therewith. For instance, a liquid cooledsink can be constructed by forming a desired serpentine copper conduitpath for liquid flow, placing the serpentine conduit construct within asink mold, pouring molten liquid aluminum into the mold and allowing themolten aluminum to cool. While this manufacturing process has been usedsuccessfully, liquid molding processes are very difficult to control andthe incidences of imperfect and or non-functioning product have beenrelatively high.

[0010] One other sink manufacturing process that has proven usefulincludes cutting a at least one channel out of a sink body member,hermetically sealing (e.g., vacuum brazing) a cover member to the bodymember to cover the channel and then forming an inlet and an outlet thatopen into opposite ends of the channel. This two part sealing process ismuch less expensive than the conduit-molten process described above.

[0011] When designing any liquid cooled heat sink several factors haveto be considered including heat dissipating effectiveness, volumerequired to accommodate a resulting converter, and cost. With respect toheat dissipation, in the case of a power conversion assembly, there aretypically several different heat generating devices that are similarlyconstructed and that operate in a similar fashion to convert power. Forinstance, as well known in the controls arts, an AC to DC rectifiertypically includes a plurality of power switching devices that arearranged to form a bridge assembly. In the case of a three phase supplyand load, the bridge assembly includes three phases, a separateswitching phase for each of the three supply and load phases. Here, anexemplary phase may include first and second power switching deviceslinked at a common node to an associated supply line where the otherterminals of the first and second switches are linked to positive andnegative DC busses, respectively. A controller is configured to controlall of the three phases of the bridge together to convert the threephase AC supply voltage to a DC potential across the positive andnegative DC busses.

[0012] In a similar fashion, a three phase inverter assembly typicallyincludes three separate phases that link positive and negative DC bussesto three load supply lines. In the case of an inverter, each phasetypically includes first and second power switching devices that arelinked in series between the positive and negative DC busses with thecommon node between the first and second inverter switches linked to anassociated phase of the load. Where the supply and load voltages arelarge, some rectifier/inverter converter assemblies may include severalthree phase bridges linked together thereby reducing the load handlingof each switching device.

[0013] In the case of a rectifier-inverter conversion assembly, a drivecircuit is provided that controls all of the switching devices togetherto create desired three phase output voltages to drive a load linkedthereto. In this case, it is imperative that the switching devicesoperate in characteristic and substantially similar ways to simplifywhat is, by its very nature, an already complex switching scheme. Forthis reason, converter designers typically select switching deviceshaving generally known operating characteristics (i.e., that operatewithin a range) to configure their conversion assemblies.

[0014] Nevertheless, as also well known, most switching devices haveoperating characteristics that are, at least in part, affected by theenvironments in which the devices operate. Specifically, for thepurposes of the present invention, it should be appreciated thatswitching device operating characteristics change as a function oftemperature. For instance, an internal switch resistance has been knownto change as a function of temperature which in turn affects the voltagedrop across the switch. While each voltage drop change that occurs mayseem insignificant, because rectifier and inverter switches aretypically turned on and off very rapidly, the affect of changing devicedrop has been shown to be appreciable.

[0015] The problems associated with voltage drop variance are compoundedwhere similar switching devices are operated at different temperaturesand is especially acute where control schemes operate to simultaneouslycontrol all three conversion assembly phases together to generate loadvoltages. Thus, for instance, where one switching device is severaldegrees hotter than another switching device, the result may beunbalanced phase voltages and hence imperfect load control (e.g.,non-smooth motor rotation) which increases overall system wear and cancause system damage over time.

[0016] For this reason, one challenge when designing a heat sink for usewith a converter assembly has been to provide essentially identical heatdissipating capacity to each converter switching device so that devicetemperatures are essentially identical during system operation. Theproblem here is that coolant temperature rises as the coolant absorbsheat along its path through a sink member so that power switchingdevices relatively near an inlet port along a serpentine coolant pathare cooled to a greater degree than switching devices down stream fromthe inlet port. One solution that reduces the heat dissipating capacitydifferential between similar switching devices has been to provide aheat sink where the spacing between a cooling liquid inlet and each ofthe sink surfaces to which switching devices are mounted is similar. Forinstance, where a configuration includes twenty four power switchingdevices, instead of mounting the switching devices to the sink in apattern that tracks a single serpentine cooling conduit path, theswitching devices may be mounted on sink member mounting surface to formsix rows of four switching devices each where each of the six rows isfed by a separate one of six liquid coolant inlet ports—here a manifoldmay serve each of the six inlet ports (see generally FIG. 23 in U.S.Pat. No. 6,031,751 (hereinafter “the '751 patent”) entitled “SmallVolume Heat Sink/Electronic Assembly” which issued on Feb. 29, 2000 andwhich is incorporated herein by reference). Thus, in this case, coolantfrom each of the six inlet ports passes by four separate heat generatingdevices and device cooling will be relatively more uniform. Thissolution to reduce the device temperature differential will be referredto hereinafter as a matrix spacing solution.

[0017] One other solution that reduces the heat dissipating capacitydifferential between switching devices mounted to a sink member has beento provide a serpentine path that passes by each heat generating devicemore than once so that the overall cooling affect of devices is similar.For instance, assume twelve switching devices are mounted to a sinkmember mounting surface to form two rows of six devices each and that asingle serpentine path is configured to include a first linear run thatpasses adjacent the first row of devices, a first 180 degree turn, asecond linear run that passes adjacent the second row of devices, asecond 180 degree turn, a third linear run that again passes adjacentthe second row of devices, a third 180 degree turn and a fourth linearrun that passes a second time by the first row of devices to an outlet.

[0018] Here, in theory, the first linear run should include the coolestcoolant, the second linear run should include the second coolest coolantand so on so that the coolant temperatures through the first and fourthlinear runs (i.e., adjacent the devices in the first row) should averageand the coolant temperatures though the second and third linear runs(i.e., adjacent the devices in the second row) should also average andthe two average temperatures should be similar (see generally FIG. 2 inthe '751 patent). This solution to reduce the device temperaturedifferential will be referred to hereinafter as an averaging solution.

[0019] While the averaging solution and the matrix spacing solution workin theory, in reality, each of these solutions have had some problemsregarding temperature differential. With respect to the matrix spacingsolution, in the example above, the fourth device along each of the sixseparate coolant paths is warmer than the first device along the samepath as liquid passing by the first three devices along the path heatsup when heat is absorbed along the path. Thus, while better than sinksthat align devices along a single serpentine cooling conduit path, thematrix solution still results in a temperature differential.

[0020] With respect to the averaging solution, it has been determinedthat, despite multi-pass designs, at least some temperature differentialstill exists between devices spaced at different locations along thecoolant conduit path. In addition, in some cases, cooling capacity mayvary over the heat dissipating surface of each heat generating device.This intra-device dissipating differential may occur as a multi passpath necessarily requires that the coolest pass (i.e., the first pass bya device) be positioned along one side of a dissipating surface so thatanother one or more passes that include relatively warmer coolant can bepositioned along the other side of the dissipating surface.

[0021] With respect to volume (i.e., the second factor above to considerwhen designing a heat sink), as with most electronics designs, all otherthings being equal, smaller is typically considered better. Thus, someprior converter configurations have provided sink members that eitherfacilitate stacking of relatively short devices adjacent elongateddevices (see FIG. 19 in the '751 patent) or, in the alternative,alignment of similar dimensions of different devices (see FIG. 13 in the'751 patent).

[0022] For instance, the '751 patent recognizes that, in addition topower switching devices, converter configuration capacitors also oftengenerate excessive heat that should be dissipated to ensure properoperation. The '751 patent also recognizes that capacitors typicallyhave a length dimension perpendicular to their heat dissipating surfacethat is much longer than the thickness dimensions of typical switchingdevices perpendicular to the device dissipating surfaces and that theswitching devices typically have a length dimension that is similar tothe capacitor length dimension. In this case, in one embodiment, the'751 patent recognizes that overall converter configuration size can bereduced by providing an L shaped sink member having two legs that form a90° angle, mounting the capacitors to an inside surface of one of thelegs and within the space defined by the two leg members and mountingthe switching devices to the outside surface of the other of the legmembers thereby aligning the similar capacitor and device lengthdimensions.

[0023] With respect to cost, unfortunately, where an L shaped heat sinkmember or, for that matter, where a sink member having sections thatreside along other than a single plane is required to stack or aligncapacitors with switching devices, the relatively inexpensive two partsealing process described above becomes much more difficult to use. Thisis because the two part sealing process generally includes vacuumsealing a flat cover member over a channel forming body member. When thechannel must reside in more than one plane and requires a more complexcover member, tolerances required to provide a suitable cover memberwould be extremely difficult to meet and the sealing process would bedifficult to perform effectively.

[0024] Thus, where the sink member must reside in two or more planes tofacilitate stacking and/or aligning, the more expensive molten-conduitprocess would likely be employed where the conduit is formed into thedesired channel shape and molten aluminum or the like is poured into amold there around. For this reason prior stacking and aligningconfigurations have proven to be relatively expensive to manufacture andoften are not suitable given cost constraints.

[0025] Also, with respect to cost, often the last converter designconsideration is how system components will be electrically linkedtogether to form a converter topology. One particularly advantageous androbust type of linking assembly is referred to generally as a laminatedbus bar. As its label implies, a laminated bus bar typically includes aplurality of metallic sheets of laminate that are layered together withinsulators between adjacent laminate sheets. Vias are formed within thelaminated assembly where links are to be made to capacitor and switchingdevice terminals. The vias automatically link the devices and capacitorsup in a desired fashion to provide an intended converter topology (e.g.,rectifier, inverter, rectifier-inverter, etc.).

[0026] Laminated bus bar cost is generally a function of the amount ofmaterial required to construct the bus, the number of laminate layersrequired to support a configuration and the overall complexity of therequired laminate member where minimal material, minimal layers andminimal contours (i.e., bends in the laminates) are all advantageous.Unfortunately, providing a configuration that uses minimal laminatematerial, requires minimal layering and restricts the laminate to asingle plane is extremely difficult given the sink member configurationsrequired to minimize overall configuration size and provide essentiallyuniform heat dissipating capacity to all switching devices mounted tothe sink. For example, where devices are arranged in rows and columns toprovide similar distances between channel inlets and devices down streamtherefrom, typically a large number of laminate layers and acorrespondingly complex labyrinth of vias are required to linkcomponents together. As another instance, where switching device lengthsare aligned with similarly dimensioned capacitor lengths the laminationbus typically requires one or, more often, several bends to accommodateconnection terminals that reside in disparate planes. In either of thesetwo cases (i.e., many layers or several laminate bends) the amount ofmaterial required to configure a laminated bus bar can be excessive andhence unsuitable for certain applications.

[0027] Yet one other cost consideration related to converter assemblieshas to do with component versatility or the ability to use convertercomponents in more than one conversion assembly. Component versatilityis particularly important with respect to the more expensive componenttypes such as, for example, the heat sink assembly, the laminated busbar, etc. In this regard, overall system costs can be reduced bydesigning sinks and laminated bus bars that can be used with variousdevice and capacitor types. For instance, assume that a first converterassembly includes a first type of switching device, a first type ofcapacitor, a first type of sink member and a first type of laminate bar.Also assume that the sink, devices and a capacitors are dimensioned suchthat when the capacitors and devices are mounted to the sink, thecapacitors connection terminals are on the same plane as the deviceconnection terminals. Here, the first laminate bus bar type can beplanar and hence relatively inexpensive.

[0028] Next assume that a designer wants to swap out a second capacitortype for the first type in the assembly where the second capacitor typehas a thickness between its dissipating surface and its connectionterminals that is different than a similarly measures thickness of thefirst capacitor type. In this case, when the capacitors are swapped, thecapacitor and device terminals will no longer reside within the sameplane and a different, perhaps custom designed, laminate will berequired to accommodate the change. In the alternative, the sink designmay be altered to accommodate the change in device and capacitorterminal planes although this solution would be relatively expensive.Similar problems occur when different switching devices are swapped intoassemblies.

[0029] On a higher level, instead of relying on component versatility toreduce costs, if demand for a converter assembly having certainoperating characteristics is high enough, a complete modular converterassembly can be efficiently (e.g., cost effectively) designed andmanufactured. While high volume exists for certain small conversionassemblies, unfortunately, larger and more complex assemblies typicallyare not sold in volumes that justify modular, pre-manufactured,designs—there just is not enough demand for complex largerconfigurations.

[0030] Even where large scale conversion assemblies having similaroperating capabilities are in relatively high demand, often these largescale assemblies require a relatively large space within an application.In many applications, while space allotted for converter components maybe sufficient, the allotted space may require a specially designedassembly. In other words, the space layout for a converter assembly in afirst application may be different than the space layout for a converterassembly in a second application despite similar conversion requirements(e.g., power, ripple limitations, etc.). This spatial limitation onconverter assembly versatility further limits volume requirements forlarge scale complex converter assemblies. Thus, at the high end,converter assemblies are often custom designed to meet operating andspatial layout requirements of specific applications and hence areexpensive.

[0031] Thus, it would be advantageous to have a heat sink assembly thatis relatively inexpensive to manufacture and yet provides substantiallysimilar heat dissipating capacity to all devices mounted thereto. Inaddition, it would be advantageous if a sink assembly of the above kindcould be used with a simplified laminate design and be used to configurerelatively compact converter assemblies. Moreover, it would beadvantageous if the sink assembly could be versatile and hence used withother converter components that have many different dimensions.Furthermore, it would be advantageous if a converter topologyconfigurable by using the sink assembly or a set of the sink assemblieshad many different uses such as, as an inverter, as a rectifier, as aDC-DC converter, as an AC-AC converter, etc., so that per converter unitcosts could be reduced appreciably by configuring versatile relativelylarge scale converter topologies.

BRIEF SUMMARY OF THE INVENTION

[0032] It has been recognized that relatively compact and inexpensiveconverter configurations can be configured by using an elongated liquidcooled heat sink to cool power switching devices. More specifically, ithas been recognized that, where switching devices are mounted in asingle row to a sink member mounting surface, the sink can be used toconfigure minimal volume converter configurations. In at least oneembodiment of the invention, the sink mounting surface has a widthdimension that is substantially similar to a width dimension ofswitching devices to be mounted thereto with the device width dimensionsaligned with the mounting surface width dimension. This single rowlimitation has several configuration advantages described below.

[0033] It has also been recognized that, with certain types ofrefrigerant, the cooling capacity differential along a cooling channelappears to be exacerbated along the channel length. For instance, thecooling capacity differential appears to be relatively pronounced in thecase of two phase refrigerants such as R-134 a and R-123. As the labelimplies, two phase refrigerants change from a liquid to a gas when heatis absorbed and hence, generally, absorb a greater amount of heat, dueto the endothermic nature of the phase change, than conventionalsingle-phase liquid refrigerants such as water—hence two phaserefrigerants are generally preferred in high efficiency heat sinks.

[0034] Moreover, it has been recognized that, unfortunately, astwo-phase refrigerants absorb heat and change phase from liquid to gas,vapor bubbles are formed within the liquid that accumulate on theinternal surfaces of the heat sink and form gas pockets. The gas pocketson the surface of the channel block refrigerant from contacting thechannel surface and hinder device heat absorption by the refrigerant.Thus, the channel surfaces on which gas pockets form end up becoming hotspots on the channel surfaces and the temperatures of devices attachedadjacent thereto rise.

[0035] Because the vapor bubbles are formed by heat absorption andbecause coolant relatively further down stream from an inlet is warmerthan coolant more proximate the inlet, relatively more vapor bubbles areformed down stream from the inlet than proximate the inlet therebycausing more gas pockets to form down stream which increases thetemperature differential along the channel length. Thus, it has beendetermined that, while coolant temperature accounts for some of thetemperature differential along a coolant channel length, much of thetemperature differential is actually due to different amounts of gasaccumulating along different sections of the channel—the gas having aninsulating effect between the channel surfaces and the coolant passingthereby. Based on these realizations it should be appreciated that thetemperature differential problem is exacerbated where sink channels areextended.

[0036] According to several embodiments of the invention, protuberancesof a character, quantity and size that increase turbulence within sinkchannels to a point where the turbulence either prohibits gas pocketsfrom forming on the channel surfaces or dislodges or breaks up gaspockets that form on the channel surfaces, are provided on at least oneof the channel surfaces. It has been found that when such protuberancesare provided within a channel, the channel can have an extended lengthwithout causing excessive temperature differentials there along. Morespecifically, it has been determined that the channel length can, in atleast one embodiment, extend substantially along an entire sink lengthwhere the sink, as indicated above, has a length to accommodate a singlerow of switching devices. For instance, where a converter configurationincludes twenty four switching devices, the twenty four devices can bearranged in a single row along the sink member mounting surface wherethe channel extends along substantially the entire sink length from aninlet to an outlet.

[0037] It has also been determine that, in at least some embodiments ofthe invention, the sink member can be juxtaposed so that the channelinlet is below the channel outlet and, more specifically, so that thechannel inlet is directly vertically below the channel outlet. Here,dislodged or broken up gas pockets, being lighter than the refrigerant,are aided by buoyancy in their movement toward the outlet at the top ofthe sink channel.

[0038] By providing an elongated sink-device assembly including devicesmounted in a single row to an elongated sink member, overall convertercost can be reduced. In this regard, the single channel sink member canbe manufactured using the two piece sealing method described above wherethe channel is bore out of a body member, a cover member is hermeticallysealed over the channel and inlet and outlet ports that open into thechannel are formed.

[0039] In addition, cost is reduced with the inventive elongatedsink-device assembly as a simplified laminated bus bar can be used withthe sink-device assembly. In this regard, where capacitors arejuxtaposed to one side of the switching devices and with capacitorterminals and device terminals positioned within a common connectionplane, the distances between capacitor terminals and the deviceterminals that the capacitor terminals are to be linked to are reducedappreciably so that less material is required to make terminalconnections. Moreover, because capacitor terminals and the deviceterminals to which the capacitor terminals are to be linked may bepositioned proximate each other, none of the laminates have to pass overother devices disposed intermediate the connecting terminals andtherefore simpler laminate and associated via designs can be employedthat include relatively small numbers (e.g., 3) of laminate layers.

[0040] Consistent with the above, at least one embodiment of theinvention includes an electronic converter assembly comprising a liquidcooled heat sink member having a sink length dimension, at least onemounting surface and first and second oppositely facing lateralsurfaces, the mounting surface and first and second lateral surfacesforming first and second lateral edges, respectively, the sink memberalso forming at least one internal channel that extends substantiallyalong the entire sink length, an inlet and an outlet that open intoopposite ends of the channel, a plurality of power switching devicesmounted side by side to the mounting surface thereby forming a singledevice row that extends substantially along the sink length, each deviceincluding intra-converter terminals that are substantially within asingle connection plane, a plurality of capacitors, each capacitorincluding capacitor connection terminals, the capacitors linked forsupport to and adjacent the sink member with the capacitor terminalsjuxtaposed substantially within the connection plane and a linkageassembly including a plurality of conductors that link the capacitorterminals to the intra-converter terminals to form a power conversiontopology.

[0041] In one embodiment each power switching device includes first andsecond oppositely facing linking edges and wherein the intra-converterterminals form the first linking edge proximate the first lateral edgeof the sink member.

[0042] Some embodiments further include a bracket member mounted to thesink member and extending past the first surface, the capacitors mountedto the bracket member for support. More specifically, the mountingsurface may be a first mounting surface and the sink member may includea second mounting surface that faces in a direction opposite the firstmounting surface wherein the bracket member is mounted to the secondmounting surface.

[0043] In some embodiments the bracket member includes a proximatemember mounted to the second mounting surface, an intermediate memberlinked to and forming a substantially 90 degree angle with the proximatemember and extending substantially parallel to the first lateral side ofthe sink member and generally away from the sink member and a distalmember forming a substantially 90 degree angle with the intermediatemember and extending generally away from the sink member, the capacitorsmounted to the distal member. Moe specifically, in one embodiment eachof the devices includes a heat dissipating surface adjacent the mountingsurface and is characterized by a device thickness dimension between theconnection plane and the dissipating surface of the device, the firstand second mounting surfaces are separated by a sink thickness, theintermediate member has an intermediate member length, each capacitorincludes first and second oppositely facing ends and a length dimensionbetween the first and second ends, the capacitor terminals extendaxially from the first end of each capacitor and the second end of eachcapacitor is mounted to the distal member and, wherein, the combinedsink thickness, device thickness and intermediate member length issubstantially similar to the capacitor length dimension.

[0044] Each capacitor may have a heat conducting extension thatprotrudes from the second end of the capacitor and that is in conductivecontact with the distal end of the bracket member. Here, the bracketmember may be formed of a heat conducting material (e.g., aluminum orcopper). In addition, here, the linkage assembly may include asubstantially planar laminated bus bar.

[0045] In some embodiments the linkage assembly links the capacitors andpower switching devices together to form an inverter while in otherembodiments the linkage assembly may link the capacitors and switchingdevices to form a rectifier. In still other embodiments the linageassembly may link the capacitors and switching devices to form both arectifier and an inverter.

[0046] The first and second lateral edges of the mounting surface mayform a sink member width and a device width between the first and secondlinking edges may be substantially similar to the sink member width.

[0047] In some embodiments the channel inlet is disposed below thechannel outlet. More specifically, the channel inlet is substantiallydirectly vertically below the channel outlet. In some embodiments theextension members may be provided that extend into the channel therebyincreasing turbulence in liquid pumped from the inlet to the outlet.

[0048] The invention also includes an electronic converter assemblycomprising a heat sink member having a sink length dimension, at leastone mounting surface and first and second oppositely facing lateralsurfaces, the mounting surface and first and second lateral surfacesforming first and second lateral edges, respectively, a plurality ofpower switching devices mounted side by side to the mounting surface toform a single device row that extends along the sink length, each deviceincluding intra-converter terminals juxtaposed substantially within asingle connection plane, each device also including first and secondoppositely facing linking edges having a device width therebetween, abracket member mounted to the sink member and extending past the firstlateral surface, a plurality of capacitors, each capacitor includingcapacitor connection terminals, the capacitors mounted to the bracketmember adjacent the sink member with the capacitor terminalssubstantially within the connection plane and a linkage assemblyincluding a plurality of conductors that link the capacitor terminals tothe intra-converter terminals to form a power conversion topology.

[0049] In some embodiments the sink member forms at least one internalchannel that extends substantially along the entire sink length and aninlet and an outlet that open into opposite ends of the channel and,wherein, the converter configuration is juxtaposed so that the channelis substantially vertically oriented. More specifically, the channelinlet may be substantially vertically below the channel outlet.

[0050] While there are many advantages associated with arranging powerswitching devices in a single line, it has also been recognized that,under certain circumstances, such an arrangement may not function well.For example, where conversion power requirements are increased, thenumber of switching devices required to handle the power level must alsobe increased. At some point, even with an efficient and well designedliquid cooled sink, the heat generated by the devices mounted theretomay cause a temperature differential along the sink length (e.g., frominlet to outlet). Thus, there is an operational or functional limitationto liquid cooled sink length.

[0051] In addition to the functional limitation on sink length, in manyapplications there are space limitations that have to be considered whendesigning a converter configuration. For instance, while long sink andswitching configurations may be suitable for some applications, in manyapplications, space allotted for the converter assembly is rectilinearand has a short maximum dimension (e.g., the length is more similar tothe width).

[0052] According to one aspect of the present invention, a high powerconverter configuration includes two liquid cooled sink members, eachmember providing a mounting surface that may receive several (e.g.,four) power switching device modules arranged in a line along itslength. Here, a single linking assembly links the switching devices inthe modules together between DC buses to form conversion bridgeassemblies. In addition, in at least some embodiments, capacitors aremounted to a single bracket member which is in turn mounted to the sinkmembers such that intra-converter module connection terminals andcapacitor connection terminals are within the same plane and a singleplanar laminated bus bar links all module switches to form converterbridges. Where a long space is provided for the conversion assembly, thesink members may be mounted end to end along one side of the bracketmember. Where a shorter relatively more rectilinear space is providedfor the conversion assembly, the bracket member may be mounted betweenand separating the first and second sink members on opposite sides ofthe laminated bus bar. Thus, compact high power conversion assembliescan be configured with minimal component count and simple componentdesign.

[0053] In the case of a two sink configuration, each of the two sinksmay have the same design as the liquid cooled sink member describedabove in the context of a converter assembly including only a singleliquid cooled sink member. Thus, converter assemblies having differentcapabilities can be configured using the same component types therebyincreasing component versatility and reducing per component costs.

[0054] According to another aspect of the present invention, in at leastsome embodiments of the invention, positive and negative DC tabs orstuds are linked to the positive and negative DC buses of a laminatedbus bar. The DC tabs increase complex converter assembly versatility andthereby to reduce per assembly costs. For instance, an exemplary complexconverter assembly may include first and second sets of power switchingdevice modules where each module includes six switching devices (i.e.,each module independently includes all of the switching devices requiredto construct a complete converter bridge). A laminated intra-converterbus bar links all of the device modules together so that a plurality ofseparate converter bridges are formed between positive and negative DCbuses where each bridge includes first, second and third switch pairs,each pair arranged in series between the DC buses. Each of three busbars in a first inter-converter bar set may be linked to the positiveand negative DC buses in the laminated bar via the switches in at leastone bridge leg (e.g., each inter-converter bar is linked to at least onecommon node between the two switches in a single switch pair). Here, DCtabs extend from the positive and negative DC buses in the laminate.

[0055] The above complex converter topology can be employed to providevarious different conversion functions. For example, the firstinter-converter bar set may be linked to an AC source, the secondinter-converter bar set may be linked to a load and the switchingdevices in the first and second module sets may be controlled so thatthe topology provides AC-AC conversion (i.e., as a rectifier and aninverter) in this case the DC tabs are not employed. As another example,the first inter-converter bar set may be linked to an AC source, thesecond bar set may not be linked to either a source or a load and the DCtabs may then be employed as a DC source for some other application.Similarly, each of the first and second inter-converter bar sets may belinked to AC sources and each of the first and second module sets may becontrolled as rectifiers to provide a higher DC voltage at the DC tabs.As one other example, an external DC source may be provided at the DCtabs and both or only one of the module sets may be controlled asinverters to provide AC output voltages at associated inter-converterbars. Still another example may include, where each module set includesmore than one module, controlling only a sub-set of the first or secondset modules to rectify or inverter power where lesser power levels arerequired.

[0056] It should be appreciated that, while the industry generally haslooked upon relatively large conversion topologies with a jaundiced eyebecause of a lack of versatility and because of limitations regardingaccommodating space layouts, by combining the inventive liquid cooledsink member concepts with specific component juxtapositions and the DCtab concept, far smaller and far more versatile complex converterassemblies can be designed and manufactured.

[0057] While various aspects of the present invention render complexconverter topologies cost effective and small enough to be suitable formany applications, one additional problem occurs when multiple powerswitching device modules are combined to increase rectifier and/orinverter power handling capabilities. In this regard, as known in theswitching device industry, despite efforts to manufacture switchingdevices that have identical operating characteristics, unfortunately,operating characteristics for devices of the same type are oftenslightly different such that turn on and off periods for the switchingdevices vary within a “tolerance range”. In the case of convertercontrol, a huge number of switching operations occur every second andthe cumulative effect of the switching differences has been known toappreciably and adversely affect conversion functions.

[0058] It has been recognized that, while switches of a specific typemay have operating characteristics that fall within some specifiedrange, the range of operating characteristics for switches mounted onthe same switching device module is typically smaller than the range ofcharacteristics of devices on different switching device modules. Forinstance, in the case of first and second modules of the same type, theoperating characteristics of the six switching devices on the firstmodule will typically be within a first small range and the operatingcharacteristics of the six switching devices on the second module willtypically be grouped within a second small range where the first andsecond ranges are different.

[0059] According to another aspect of the present invention,inter-converter bus bars have been designed wherein each bus bar linksto switching devices on several different switching device modules sothat the different switching device operating characteristics can beaveraged among the different converter phases. For instance, in at leastsome embodiments of the invention where two modules are used to linkfirst, second and third inter-converter bus bars to DC buses, each ofthe bus bars is linked to a separate switching device pair in each ofthe modules (e.g., a first bar may be linked to the common node of afirst switching device pair in each of the first and second modules, asecond bar may be linked to the common node of a second switching devicepair in each of the first and second modules and a third bar may belinked to the common node of a third switching device pair in each ofthe first and second modules). Where additional modules are used to linkthe inter-converter bars to the DC buses, each bar is linked to a devicepair in each of the additional modules.

[0060] Consistent with the above, the present invention also includes anelectronic converter assembly comprising first and second liquid cooledheat sink members, each sink member having at least one sink mountingsurface, first and second pluralities of power switching devices, eachswitching device including connection terminals, the first and secondpluralities of switching devices mounted to the first and second sinkmounting surfaces, respectively and a planar laminated bus bar includinga plurality of conductors that link the power switching deviceconnection terminals to form a power conversion topology.

[0061] In some embodiments further include a bracket member and aplurality of capacitors, the bracket member having at least one bracketmounting surface and rigidly mounted to each of the first and secondsink members, the capacitors mounted to the bracket mounting surface andthe laminated bar further linking the switching device connectionterminals and the capacitors to form the conversion topology. Here, thebracket member may be mounted between the first and second sink membersand first lateral surfaces of the first and second sink members may faceeach other. Moreover, each capacitor may include a mounting end and acapacitor connection terminal at an end opposite the mounting end, maybe mounted to the bracket mounting surface at the mounting end and maybe dimensioned such that the connection terminal is substantiallycoplanar with the switching device connection terminals.

[0062] In at least some embodiments the bracket member includes firstand second lateral end members mounted to the second mounting surfacesof the first and second sink members, respectively, first and secondintermediate members linked to and forming substantially 90 degreeangles with the first and second proximate members and extendingsubstantially parallel to the first lateral sides of the first andsecond sink members and generally away from the first and second sinkmembers, respectively, and a central member linked between the first andsecond intermediate members, forming a substantially 90 degree anglewith each of the intermediate members and extending generally betweenthe first and second sink members, the capacitors mounted to the centralmember. Here, each of the devices includes a heat dissipating surfaceadjacent the mounting surface and is characterized by a device thicknessdimension between the connection plane and the dissipating surface ofthe device, the first and second mounting surfaces on each of the sinkmembers are separated by a sink thickness, each of the first and secondintermediate members has an intermediate member length, each capacitorincludes first and second oppositely facing ends and a length dimensionbetween the first and second ends, the capacitor terminals extendaxially from the first end of each capacitor and the second end of eachcapacitor is mounted to the central member and, wherein, the combinedsink thickness, device thickness and intermediate member length issubstantially similar to the capacitor length dimension.

[0063] In some cases the first sink member has a first length dimensionand forms a first internal channel along its length dimension between aninlet and an outlet and wherein the second sink member has a secondlength dimension and forms a second internal channel along its lengthdimension between an inlet and an outlet. The sink members may beoriented such that the first sink member inlet is below the first sinkmember outlet and the second sink member inlet is below the second sinkmember outlet. More specifically, the sink members may be oriented suchthat the channels are substantially vertically oriented.

[0064] In some embodiments each of the first and second sink members hasfirst and second oppositely facing lateral surfaces, the mountingsurfaces and first and second lateral surfaces form first and secondlateral edges, respectively, on each of the sink members, the bracketmember mounted to the sink members such that the first lateral surfacesof the first and second sink members oppose each other. In aparticularly detailed configuration the first plurality of powerswitching devices is mounted side by side on the first sink mountingsurface forming a single row that extends substantially along the firstsink length, each device in the first plurality includingintra-converter terminals juxtaposed within a first connection plane andwherein the second plurality of power switching devices is mounted sideby side on the second sink mounting surface forming a single row thatextends substantially along the second sink length, each device in thesecond plurality including intra-converter terminals that are alsojuxtaposed within the first connection plane wherein the intra-converterconnection terminals are the terminals linked to the laminated bus bar.

[0065] The intra-converter terminals of each device may be locatedproximate the first lateral edge of the sink member to which the deviceis mounted. Similarly, the inter-converter terminals of each device maybe located proximate the second lateral edge of the sink member to whichthe device is mounted and are within the first connection plane.

[0066] The invention also includes an electronic converter assemblycomprising first and second liquid cooled heat sink members, each sinkmember having at least one sink mounting surface and a length dimension,each sink member forming an internal substantially vertical channelbetween an inlet and an outlet where the inlet is below the outlet, abracket member rigidly linked to the first and second sink members,first and second pluralities of power switching devices mounted to thefirst and second sink mounting surfaces, respectively, each switchingdevice including intra-converter connection terminals and a linkageassembly including a plurality of conductors that link the powerswitching device intra-converter connection terminals to form a powerconversion topology. In some embodiments the bracket member is mountedbetween the first and second sink members.

[0067] The invention also includes a method for configuring a converterassembly, the method comprising the steps of providing first and secondliquid cooled heat sink members where each member has a mounting surfaceand has a length dimension, each mounting surface having first andsecond lateral edges that extend along the length dimension and thatface in opposite directions, mounting a bracket member to the sinkmembers such that the sink member length dimensions are substantiallyparallel, providing first and second pluralities of power switchingdevices where each device includes inter-converter connection terminalsto be linked to a source or a load and intra-converter connectionterminals to be linked to either a positive or a negative DC bus,mounting the first and second pluralities of switching devices to thefirst and second sink member mounting surfaces with the intra-converterand the inter-converter connection terminals proximate the first andsecond edges of the mounting surfaces, respectively and linking theintra-converter connection terminals to positive and negative DC busesto form the converter topology.

[0068] In some cases the step of mounting the bracket member to the sinkmembers includes mounting the bracket member between the first andsecond sink members such that the first edges of the sink members faceeach other. In some cases the method further includes the step oforienting the first and second sink members such that the lengthdimensions are substantially vertically oriented. In some embodimentsthe step of linking includes providing a laminated bus bar includingpositive and negative DC bus conducting layers and linking theintra-converter connection terminals to the positive and negative layersto configure the topology.

[0069] The invention also includes an apparatus for linking togetherpower switching devices having intra-converter connection terminals toform a power conversion assembly, the apparatus comprising a planarlaminated bus bar including positive and negative DC bus layers andinsulating layers that insulate each of the DC bus layers, the bar alsoincluding at least a first external insulating layer that forms a firstexternal surface of the bar, the bar also forming at least first andsecond linking edges and first and second pluralities of linkages formedalong the first and second linking edges, respectively, each linkagelinked to one of the positive and negative DC bus layers and configuredto be linkable to at least one of the power switching deviceintra-converter connection terminals.

[0070] In some of the embodiments each of the linkages is a linking tab.In some cases the first and second edges of the bus bar face in oppositedirections. In some embodiments the bus bar is substantiallyrectilinear. In some embodiments the first and second edges are straightand the first plurality of linkages are aligned along the first straightedge and the second plurality of linkages are aligned along the secondstraight edge. In some cases the first and second linking edges arevertically aligned.

[0071] Some cases include first and second external linking vias thatopen to the positive and negative DC bus layers, respectively. Someembodiments further include positive and negative DC connectionterminals that extend through the first and second vias and are linkedto the positive and negative DC bus layers, distal ends of the DCconnection terminals exposed and connectable to at least one of a DCsource and a DC load.

[0072] According to one aspect the apparatus is for linking at leastfirst and second bridge assemblies together with capacitors to form aconversion device wherein, each of the linkages in the first pluralityis linked to at least one of the intra-converter connection terminals ofthe first bridge assembly and each of the linkages in the secondplurality is linked to at least one of the intra-converter connectionterminals of the second bridge assembly.

[0073] The invention further includes a three phase electronic converterassembly comprising at least a first heat sink member having a mountingsurface, first and second X phase converter bridge assemblies, eachbridge assembly including a plurality of power switching devices, thefirst bridge assembly forming first through Xth external linkageterminals and the second bridge assembly forming (X+1)th through 2Xthexternal linkage terminals, each linkage terminal linkable to one phaseof at least one of an X phase source and an X phase load, the switchingdevices mounted to the mounting surface of the at least first sinkmember, a plurality of capacitors and a laminated bus bar including apositive DC bus, a negative DC bus and a plurality of insulating layersthat insulate the positive and negative DC buses and form an externalinsulating layer, the linkage assembly linking the plurality ofcapacitors and each of the bridge assemblies between the positive andnegative DC buses, the bar forming first and second external linkingvias that open to the positive and negative DC buses, respectively.

[0074] The invention moreover includes a three phase electronicconverter assembly comprising a first heat sink member having a mountingsurface, a second heat sink member having a mounting surface, first andsecond X phase converter bridge assemblies, each bridge assemblyincluding a plurality of power switching devices, the first bridgeassembly forming first through Xth external linkage terminals and thesecond bridge assembly forming (X+1)th through 2Xth external linkageterminals, each linkage terminal linkable to one phase of at least oneof an X phase source and an X phase load, the first assembly switchingdevices mounted to the first sink member mounting surface and the secondassembly switching devices mounted to the second sink member mountingsurface, a plurality of capacitors and a laminated bus bar including apositive DC bus, a negative DC bus and a plurality of insulating layersthat insulate the positive and negative DC buses and form an externalinsulating layer, the linkage assembly linking the plurality ofcapacitors and each of the bridge assemblies between the positive andnegative DC buses, the external insulating layer forming first andsecond vias that open to the positive and negative DC buses,respectively.

[0075] Consistent with another aspect of the invention, an electronicconverter assembly may comprise a first heat sink member having at leasta first mounting surface and a length dimension, a plurality of powerswitching device modules wherein each module includes at least fourseparate power switching devices, the modules mounted to the first sinkmounting surface such that the switching devices are aligned along thelength of the sink member, each switching device includinginter-converter connection terminals linkable to at least one of a loadand a source and intra-converter connection terminals linkable, eachintra-converter connection terminal linkable to at least one of apositive and a negative DC bus, first, second and third bus bars, eachbus bar linked to the inter-converter connection terminals of at leastfirst and second pairs of the power switching devices where the at leastfirst and second pairs of power switching devices linked to specificones of the bus bars are from different switching device modules and alinkage assembly including a plurality of conductors that link theintra-converter connection terminals of the power switching devices toform a power conversion topology.

[0076] Some embodiments further include fourth, fifth and sixth bus barsand, wherein, the linkage assembly links the intra-converter connectionterminals to form at least first and second converter bridges, thefirst, second and third bus bars linked to the inter-converterconnection terminals of the switching devices that form the firstconverter bridge and the fourth, fifth and sixth bus bars linked to theinter-converter connection terminals of the switching devices that formthe second converter bridge.

[0077] In some cases the modules include at least first and secondmodules, each of the modules includes first, second, third, fourth,fifth and sixth switching devices aligned in a row where the first andsecond devices form a first device pair, the third and fourth devicesform a second device pair and the fifth and sixth devices form a thirddevice pair on each module, the linkage assembly linking theintra-converter connection terminals of each of the first, third andfifth switching devices in each module to a positive DC bus and linkingthe intra-converter connection terminals of each of the second, fourthand sixth switching devices in each module to a negative DC bus, thefirst bus bar linked to the inter-converter connection terminals of thefirst pair of devices of each module, the second bus bar linked to theinter-converter connection terminals of the second pair of devices ofeach of each module and the third bus bar is linked to theinter-converter connection terminals of the third pair of devices ofeach of each module. In other cases the modules further include a thirdmodule that includes first, second, third, fourth, fifth and sixthswitching devices, the linking assembly further linking theintra-converter connection terminals of each of the first, third andfifth switching devices in the third module to the positive DC bus andlinking the intra-converter connection terminals of each of the second,fourth and sixth switching devices in the third module to the negativeDC bus, the first bus bar also linked to the inter-converter connectionterminals of the first and second switching devices of the third module,the second bus bar linked to the inter-converter connection terminals ofthe third and fourth switching devices of the third module and the thirdbus bar linked to the inter-converter connection terminals of the fifthand sixth switching devices of the third module. In still another casethe modules further include a fourth module that includes first, second,third, fourth, fifth and sixth switching devices, the linking assemblyfurther linking the intra-converter connection terminals of each of thefirst, third and fifth switching devices in the fourth module to thepositive DC bus and linking the intra-converter connection terminals ofeach of the second, fourth and sixth switching devices in the fourthmodule to the negative DC bus, the first bus bar also linked to theinter-converter connection terminals of the first and second switchingdevices of the fourth module, the second bus bar linked to theinter-converter connection terminals of the third and fourth switchingdevices of the fourth module and the third bus bar linked to theinter-converter connection terminals of the fifth and sixth switchingdevices of the fourth module.

[0078] In some embodiments the first through fourth modules are a firstmodule set, the apparatus further including a second heat sink member, asecond module set and fourth, fifth and sixth bus bars, the second sinkmember having at least a first mounting surface and a length dimension,the second module set including fifth through eighth power switchingdevice modules, the fifth through eighth modules mounted to the secondsink mounting surface such that the switching devices that comprise thesecond module set are aligned along the length of the second sinkmember, the linkage assembly linking the intra-converter connectionterminals of each of the first, third and fifth switching devices ineach module to a positive DC bus and linking the intra-converterconnection terminals of each of the second, fourth and sixth switchingdevices in each module to a negative DC bus, the fourth bus bar linkedto the inter-converter connection terminals of the first and secondswitching devices on each of the fifth, sixth, seventh and eighthmodules, respectively, the fifth bus bar linked to the inter-converterconnection terminals of the third and fourth switching devices on eachof the fifth, sixth, seventh and eighth modules, respectively, the sixthbus bar linked to the inter-converter connection terminals of the fifthand sixth switching devices on each of the fifth, sixth, seventh andeighth modules, respectively.

[0079] Some embodiments further include a bracket member and a pluralityof capacitors, the bracket member rigidly mounted between and separatingthe first and second heat sink members and having a bracket mountingsurface that faces in the same direction as each of the first and secondsink mounting surfaces, the capacitors mounted to the bracket mountingsurface and linked to the linkage assembly conductors to form a part ofthe conversion topology.

[0080] In some cases the first bus bar includes a first bus spine memberand a plurality of first bus rib members linked to the first spinemember and extending laterally therefrom, each of the first rib memberslinked to at least two of the inter-converter terminals on one of thedevice modules and linked to no more than two inter-converter terminalson each of the device modules, the second bus bar including a second busspine member and a plurality of rib members linked to the second busspine member and extending laterally therefrom, each of the second ribmembers linked to at least two of the inter-converter terminals on oneof the device modules and linked to no more than two inter-converterterminal on each of the device modules, the third bus bar including athird bus spine member and a plurality of rib members linked to thethird spine member and extending laterally therefrom, each of the thirdrib members linked to at least two of the inter-converter terminals onone of the device modules and linked to no more than two inter-converterterminal on each of the device modules. In some embodiments each of themodules includes first, second, third, fourth, fifth and sixth switchingdevices and, wherein, the first bus bar includes a separate rib memberfor each pair of first and second switching devices in each of themodules, the second bus bar includes a separate rib member for each pairof third and fourth switching devices in each of the modules and thethird bus bar includes a separate rib member for each pair of fifth andsixth switching devices in each of the modules.

[0081] The invention further includes an electronic converter assemblycomprising a heat sink member having at least a first mounting surface,a length dimension and first and second oppositely facing lateralsurfaces that extend parallel to the length dimension, the mountingsurface and first and second lateral surfaces forming first and secondlateral edges, respectively, first, second, third and fourth powerswitching device modules wherein each module includes first, second,third, fourth, fifth and sixth separate power switching devices, eachswitching device including inter-converter connection terminals andintra-converter connection terminals that extend from the device inopposite directions, the modules mounted to the sink mounting surfacesuch that the switching devices are aligned along the length of the sinkmember with the intra-converter connection terminals proximate the firstlateral edge and the inter-converter terminals proximate the secondlateral edge and first, second and third bus bars, each of the bus barslinked to a sub-set of the connection terminals of switching devices inat least two different device modules.

[0082] Other embodiments include an electronic converter assemblycomprising a first heat sink member having at least a first mountingsurface, a length dimension and first and second oppositely facinglateral surfaces that extend parallel to the length dimension, themounting surface and first and second lateral surfaces forming first andsecond lateral edges, respectively, a second heat sink member having atleast a first mounting surface, a length dimension and first and secondoppositely facing lateral surfaces that extend parallel to the lengthdimension, the mounting surface and first and second lateral surfaces ofthe second sink member forming first and second lateral edges,respectively, first and second module sets, the first module setincluding first, second, third and fourth power switching device modulesand the second module set including fifth, sixth, seventh and eighthpower switching device modules wherein each module includes first,second, third, fourth, fifth and sixth separate power switching devices,each switching device including inter-converter connection terminals andintra-converter connection terminals that extend from the associatedmodule in opposite directions, the modules in the first module setmounted to the first sink member mounting surface such that theswitching devices are aligned along the length of the first sink member,the intra-converter connection terminals proximate the first lateraledge and the inter-converter terminals proximate the second lateral edgeof the first sink member, the modules in the second module set mountedto the second sink member mounting surface such that the switchingdevices are aligned along the length of the second sink member, theintra-converter connection terminals proximate the first lateral edgeand the inter-converter terminals proximate the second lateral edge ofthe second sink member, first, second, third, fourth, fifth and sixthbus bars, each of the first, second and third bus bars linked to theinter-converter connection terminals of switching devices in at leasttwo different device modules in the first module set and each of thefourth, fifth and sixth bus bars linked to the inter-converterconnection terminals of switching devices in at least two differentdevice modules in the second module set and a linkage assembly linkingthe intra-converter connection terminals of the switches in each of thefirst, second, third, fourth, fifth, sixth, seventh and eighth modulestogether to form the converter topology.

[0083] The invention also includes a bus bar assembly for use with anelectronic converter assembly having a plurality of switching devicemodules, each module including first, second and third pairs of powerswitching devices, each pair including a first device linked to apositive DC bus and a second device linked to a negative DC bus, thefirst and second devices of each pair having adjacent inter-converterconnection terminals aligned along an edge of the sink member, theassembly comprising a first rigid bus bar linkable to theinter-converter connection terminals of the first pair of switchingdevices in each module, a second rigid bus bar linkable to theinter-converter connection terminals of the second pair of switchingdevices in each module and a third rigid bus bar linkable to theinter-converter connection terminals of the third pair of switchingdevices in each module.

[0084] These and other objects, advantages and aspects of the inventionwill become apparent from the following description. In the description,reference is made to the accompanying drawings which form a part hereof,and in which there is shown a preferred embodiment of the invention.Such embodiment does not necessarily represent the full scope of theinvention and reference is made therefore, to the claims herein forinterpreting the scope of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0085]FIG. 1a is a schematic diagram of a rectifier configuration andcorresponding controller while FIG. 1b is a schematic diagram of aninverter configuration;

[0086]FIG. 2 is an exploded perspective view of a converter assemblyaccording to one embodiment of the present invention;

[0087]FIG. 3 is an exploded perspective view of the heat sink member andswitch packages of FIG. 2;

[0088]FIG. 4 is a side plan view of an assembled configurationconsistent with FIG. 2;

[0089]FIG. 5 is a bottom plan view of the conversion configuration ofFIG. 4;

[0090]FIG. 6 is a plan view of the body member of the heat sink memberof FIG. 3 and, in particular, showing the surface of the body member inwhich a coolant channel is formed;

[0091]FIG. 7 is similar to FIG. 6, albeit illustrating a secondembodiment of the body member;

[0092]FIG. 8 is similar to FIG. 6, albeit illustrating yet one otherembodiment of the body member;

[0093]FIG. 9 is a flow chart according to one aspect of the presentinvention;

[0094]FIG. 10a a schematic diagram of a rectifier configuration andcorresponding controller while FIG. 10b is a schematic diagram of ainverter configuration;

[0095]FIG. 11 is an exploded perspective view of a converter assemblyaccording to one embodiment of the present invention;

[0096]FIG. 12 is a side plan view of an assembled configurationconsistent with FIG. 11;

[0097]FIG. 13 is a top plan view of the converter configuration of FIG.12;

[0098]FIG. 14 is a schematic diagram similar to the diagram illustratedin FIG. 10a, albeit illustrating a different linkage pattern of inputlines to common nodes;

[0099]FIG. 15 is a schematic diagram illustrating switching modules anda second bus bar embodiment;

[0100]FIG. 16 is similar to FIG. 15, albeit illustrating a thirdembodiment of an inventive bus bar configuration;

[0101]FIG. 17 is a cross-sectional view of a bus bar showing vias andextending external positive and negative linkage terminals;

[0102]FIG. 18 is a flow chart illustrating a method of configuring aversatile converter topology according to the one aspect of the presentinvention; and

[0103]FIG. 19 is a schematic top plan view diagram of an additionalconverter configuration according to one aspect of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0104] Referring now to the drawings where in like numerals correspondto similar elements throughout the several views and, more specifically,referring to FIGS. 1a and 1 b, the present invention will be describedin the context of exemplary motor control system 10 including arectifier assembly generally illustrated in FIG. 1a which feeds aninverter assembly generally illustrated in FIG. 1b where each of therectifier and inverter are controlled by a controller 22. As known inthe controls industry, rectifier (FIG. 1a) receives three-phase ACvoltage on input lines 12, 14 and 16 and converts that three-phasevoltage to a DC potential across positive and negative DC buses 18 and20, respectively. The DC buses 18 and 20 generally feed the inverterconfiguration (see again FIG. 1b) which converts the DC potential tothree-phase AC voltage waveforms that are provided to a three-phase loadvia first, second and third inverter output lines 24, 26 and 28,respectively.

[0105] The rectifier assembly includes twelve separate switching devicesidentified by numerals 30-41. The switching devices 30-41 are arrangedbetween the positive and negative DC buses 18 and 20, respectively, toprovide six separate rectifier legs. Each rectifier leg includes twoseries connected switching devices that traverses the distance betweenthe positive and negative DC buses 18 and 20, respectively. For example,a first rectifier leg includes switches 30 and 36 that are in seriesbetween positive bus 18 and negative bus 20, a second rectifier legincludes switches 31 and 37 that are series connected between buses 18and 20, a third rectifier leg includes switches 32 and 38 that areseries connected between buses 18 and 20, and so on. The nodes betweenswitches in each rectifier leg are referred to as common nodes. Onecommon node between switches 32 and 38 is identified by numeral 46.

[0106] Each of input lines 12, 14 and 16 is separately linked to twodifferent common nodes. For example, as illustrated, line 14 is linkedto common node 46 between switches 32 and 38 and is also linked to thecommon node (not numbered) between switches 33 and 39. In a similarfashion, input line 12 is linked to the common node between switches 34and 40 and also to the common node between switches 35 and 41 while line16 is linked to the common node between switches 30 and 36 and to thecommon node between switches 31 and 37. In FIG. 1a (and also FIG. 1bdescribed below) switch emitters, collectors and gates are identifiedvia E, C and G labels, respectively, with the collectors and emitters ofswitches 30 and 36 qualified by “1” and “2” sub-labels (e.g., E1, E2,C1, C2), to distinguish those emitters and collectors for additionalexplanation below.

[0107] A control bus 48 which represents a plurality of differentcontrol lines links controller 22 separately to each one of therectifier switches 30-41 for independent control. Controller 22 controlswhen each of the switches 30-41 turns on and when each of the switches30-41 turns off. Control schemes that may be used by controller 22 toconvert the three-phase voltages on lines 12, 14 and 16 to a DCpotential across DC buses 18 and 20 are well known in the conversion artand therefore will not be described herein detail. Rectifier legs thathave their common nodes (e.g., 46) linked to the same input line arecontrolled in an identical fashion by controller 22. For example,referring still to FIG. 1a, each of switches 32 and 33 would be turnedon and turned off at the same time by controller 22 and each of switches38 and 39 would be turned on and turned off at the same times bycontroller 22 as the corresponding rectifier legs have the same commonnode 46 linked to line 14.

[0108] In addition to the components described above, the rectifierconfiguration illustrated in FIG. 1a also includes capacitors between DCbuses 18 and 20 which are collectively identified by numeral 50.Although only two capacitors are illustrated, it should be appreciatedthat a larger number of capacitors would typically be employed in anytype of rectifier configuration. Capacitors 50 reduce the ripple in thepotential between lines 18 and 20 as well known in the art.

[0109] Referring now to FIG. 1b, the inverter configuration illustrated,like the rectifier configuration of FIG. 1a, includes twelve separateswitching devices identified by numerals 61-72. The switching devices61-72 are arranged to form six separate inverter legs. Each inverter legincludes a pair of the switching devices 61-72 that is series arrangedbetween the positive DC bus 18 and the negative DC bus 20. For example,a first inverter leg includes switches 61 and 67 series arranged betweenbuses 18 and 20, a second inverter leg includes switches 62 and 68series arranged between buses 18 and 20, a third leg includes switches63 and 69 series arranged between buses 18 and 20, and so on.

[0110] Common nodes between inverter leg switch pairs are referred tohereinafter as common nodes. In FIG. 1b, an exemplary common nodebetween switches 61 and 67 is identified by numeral 80. In theillustrated embodiment, each output line 24, 26 and 28 is linked to twoseparate inverter leg common nodes (e.g., 80). For example, output line28 is linked to common node 80 between switches 61 and 67 and is alsolinked to the common node (not illustrated) between switches 62 and 68.Similarly, output line 26 is linked to the common node between switches63 and 69 and also to the common node between switches 64 and 70 whileoutput line 24 is linked to the common node between switches 65 and 71and is also linked to the common node between switches 66 and 72.

[0111] The control bus 48 linked to controller 22 is also linkedseparate to each of the inverter switches 61-72 to independently controlthe turn on and turn off times of those switches. As in the case of therectifier switches of FIG. 1a, controller 22 controls the switches ofthe inverter legs that have common nodes linked to the same output linein an identical fashion. To this end, referring still to FIG. 1b,because the common nodes (e.g., 80) corresponding to the first inverterleg including switches 61 and 67 and the second inverter leg includingswitches 62 and 68 are both connected to output line 28, the first andsecond inverter legs are controlled in a similar fashion so that each ofswitches 61 and 62 is turned on and turned off at the same times andeach of switches 67 and 68 are turned on and off at the same times.

[0112] Referring to FIGS. 1a and 1 b, the rectifier-inverterconfiguration includes commonly controlled switches so that theconfiguration can handle relatively high currents that may otherwisedestroy the types of devices employed to configure the converters. Inthis manner relatively less expensive switches can be used to constructthe converter assembly. The switches 30-41 used to configure therectifier are typically identical and the switches 61-72 used toconfigure the inverter are typically identical. Depending on theconfiguration design, switches 30-41 may or may not be identical toswitches 61-72.

[0113] Referring still to FIGS. 1a and 1 b, switch manufacturers oftenprovide power switching devices in prepackaged modules suitable toconstruct inverters and rectifiers. To this end, often, a complete6-switch bridge will be provided as a separate and unique switchingpower package. Hereinafter it will be assumed that the 24 switches thatcomprise the rectifier and inverter in FIGS. 1a and 1 b are provided infour separate 6-switch bridge packets where the first switching packageincludes switches 30, 31, 32, 36, 37 and 38, the second switch packageincludes switches 33, 34, 35, 39, 40 and 41, the third switch packageincludes switches 61, 62, 63, 67, 68 and 69 and the fourth switchpackage includes switches 64, 65, 66, 70, 71 and 72. Unless indicatedotherwise, hereinafter, the first, second, third and fourth switchpackages will be identified by numerals 90, 92, 94 and 96, respectively.Exemplary switch packets 90, 92, 94 and 96 are illustrated in FIG. 2 andare described in greater detail below.

[0114] Referring now to FIG. 2, an exploded perspective view of anexemplary rectifier/inverter converter assembly 100 is illustrated.Configuration 100 includes a heat sink member 102, the four powerswitching device modules 90, 92, 94 and 96 briefly described above, abracket member 104, a plurality of capacitors collectively identified bynumeral 50, a laminated bus bar 106 and a plurality of input and outputbus bars identified by numerals 12′, 14′, 16′, 28′, 26′, and 24′.

[0115] Each of switch packages 90, 92, 94 and 96 is similarlyconstructed and therefore, in the interest of simplifying thisexplanation, unless indicated otherwise, only switch package 90 will bedescribed here in detail. Referring also to FIGS. 3 and 5, package 90has a generally rectilinear shape having a length dimension L3, a widthdimension W1 and a thickness dimension (not separately labeled).Although not illustrated in any of the drawings, device package 90 ischaracterized by a device thickness dimension that will be referred toherein by label T1 that is formed between the mounting or dissipatingsurface 122 (see FIG. 3) of the device and a connection plane defined bythe top surfaces of the emitter and capacitor connection terminals thatextend from the package housing. Package 90 has a first device or firstlinking edge 130 and a second device or second linking edge 132 thatface in opposite directions and are separated by device width W1 asillustrated.

[0116] Referring still to FIG. 1a and also to FIG. 2, package 90includes switching devices 30, 31, 32, 36, 37 and 38 that are arrangedin a single row relationship where the emitters and collectors for eachone of the switching devices extend from opposite side of package 90 andare generally separated by the device width W1. For example, the emitterE1 and collector C1 extend from opposite sides of package 90 whileemitter E2 and collector C2 for switch 36 extend in opposite directions.Adjacent switches within package 90 have their emitters and collectorsextending in different directions. For example, referring to FIG. 1a andFIG. 2, switch 36 in FIG. 1a has its emitter E2 and its collector C2extending in directions opposite those of emitter E1 and collector C1 ofthe first switch 30 adjacent thereto in the package 90. Referring stillto FIG. 3, package 90 is designed so that all of the emitter andcollector terminals extend from the package housing within a singleconnection plane.

[0117] Hereinafter, unless indicated otherwise, switching deviceconnection terminals that are linked to any of bus bars 12′, 14′, 16′,24′, 26′ or 28′ will be referred to as inter-converter terminals becausethose terminals are connected through their respective bus bars tocomponents outside the converter configuration. Similarly, any devicepackage terminals that are linked to laminated bus bar 106 will bereferred to hereinafter generally as intra-converter terminals as thoseterminals are linked to other components within the converter assembly.

[0118] As illustrated and described hereinafter, all of theinter-converter terminals extend from one side of package 90 while allof the intra-converter terminals extend from the opposite side ofpackage 90 after the configuration in FIGS. 2 and 4 is assembled. Inaddition, after assembly, all of the intra-converter terminals for allof packages 90, 92, 94 and 96 extend in the same direction and form aconnection line while all of the inter-converter terminals for packages90, 902, 904 and 96 extend in the opposite direction and form a secondconnection line (see alignment generally in FIG. 2). The first andsecond connection lines form linking edges of the devices in thepackages.

[0119] Control ports are provided on a top surface of package 90 tofacilitate linking of control bus 48 to the devices provided withinpackage 90. An exemplary control port in FIG. 2 is identified by numeral120.

[0120] Package 90 has an undersurface 122 that is in thermal contactwith the components inside the package housing that generate heat.Package 90 is designed so that surface 122 is substantially flat and canmake substantially full contact with a heat sink surface when mountedthereto. It should be appreciated that, typically, only a portion ofsurface 122 may generate a relatively large percentage of the totalamount of heat generated by the package and that the primary heatgenerating surface will likely be the central portion of surface 122. Aheat generating segment 124 or dissipating surface of package 92 isillustrated and includes a space that is framed by an outer space 126that surrounds the heat generating space 124. Space 124 generallycorresponds to a space that is in direct contact with the package 90components that conduct current and hence generate heat. Space 124 has adissipating surface width dimension W2 associated therewith.

[0121] As best in seen in FIGS. 2 and 3, each package 90 includes aplurality of small apertures, two of which are identified by number 128,provided through the outer space 126 that frames the heat generatingsegment 124 (e.g., see device 92) as illustrated. Apertures 128 areprovided to facilitate mounting packages 90, 92, 94 and 96 to sinkmember 102.

[0122] Referring still to FIG. 2, bus bars 12′, 14′, 16,′ 28′, 26′ and24′ are to be linked to input lines 12, 14, 16 and output lines 28, 26and 24 in FIGS. 1a and 1 b, respectively. The linking relationshipbetween bus bars and associated lines is highlighted by the bus barsbeing labeled with numbers that are identical to the line numbers towhich they connect followed by a “′” indicator.

[0123] Each of input and output bus bars 12′, 14′, 16′, 24′, 26′ and 28′are simply steel bars that either have an “L” shape or a “T” shape. Eachbar 12′, 14′, 16′, 24′, 26′ and 28′ is designed to link input or outputlines to a subset of four of the inter-converter terminals. For example,referring to FIGS. 1a and 2, L-shaped bus bar 16′ is constructed anddimensioned so as to link together each of the emitter E1 for switch 30,the collector C2 for switch 36, the emitter for switch 31 and thecollector for switch 37 and, to this end, includes four separateapertures for receiving some type of mechanical securing component(e.g., a bolt), a separate aperture corresponding to each one theemitters and collectors to be connect by bar 16′. Each of the other busbars 12′, 14′, 24′, 26′ and 28′ has a construction similar to bus bar16′ and therefore, in the interest of simplifying this explanation, theother bars will not be described here in detail. It should suffice tosay that the bus bars link emitters and collectors among the switchpackages 90, 92, 94 and 96 in a manner that is consistent with theschematics illustrated in FIGS. 1a and 1 b.

[0124] Referring once again to FIG. 3 and also to FIG. 4, heat sinkmember 102 is an elongated and, in the illustrated embodiment,substantially rectilinear metallic (e.g., aluminum, copper, etc.) memberthat extends from a first end 144 to a second end 146, has first andsecond lateral surfaces 148 and 150, respectively, that face in oppositedirections and extend along the entire length between ends 144 and 146and also includes a first or first mounting surface 140 and a secondoppositely facing mounting surface 142. As best illustrated in FIG. 2(and also illustrated in FIG. 6), mounting surface 140 has a widthdimension W3 that separates the lateral surfaces 148 and 150,respectively and has a length dimension L5. Mounting surface 140 andlateral surfaces 148 and 150 form first and second lateral edges 149 and151, respectively. In at least one embodiment of the present invention,sink width W3 is substantially similar to the device package width W1 sothat, as illustrated in FIG. 2, device packages 90, 92, 94 and 96 aremounted in a side-by-side single row fashion to be accommodated onmounting surface 140.

[0125] As best seen in FIG. 3, in at least one embodiment, sink member102 includes two separate components that are secured together. The twocomponents including a body member 160 and a cover member 162. Referringalso to FIG. 5, body member 160 has thickness dimension T2 which isgenerally greater than the thickness dimension (not separatelyidentified) of member 162. Together, body member 160 and cover member162 have a thickness dimension T3.

[0126] As illustrated in FIGS. 3 and 6, body member 160 includes asecond surface 164 opposite mounting surface 140 and forms a cavity 166therein which extends substantially along the length of body member 160from the first end 144 of the sink member to the second end 146. Cavity166 has a cavity or channel depth Dc and forms a cavity or channelsurface 69. In the illustrated embodiment, cavity 166 stops short ofeach of the ends 140 and 146, has a cavity length dimension L4 and has acavity width or receiving dimension W4. Channel walls are provided onopposite sides of cavity 166 that have a thickness that is similar tothe width dimension of the framing (i.e., the mounting flange) portion126 of device surface 122 (see FIG. 3). The cavity width dimension W4,in at least some embodiments, is similar to the width dimension W2 ofthe primary heat generating portion or segment 124 of the packagedissipating surface 122.

[0127] Cavity length dimension L4, in some embodiments, is substantiallysimilar to a dimension formed by the oppositely facing edges of thedissipating surfaces of the device packages at the ends of the devicerow attached to the sink member. This dimension will be slightly smallerthan the combined lengths (e.g., L3) of the device packages 90, 92, 94and 96 in most cases. When cavity 160 is so dimensioned, a relativelysmall sink assembly is constructed which still provides effectivecooling to devices attached thereto.

[0128] Referring still to FIGS. 3 and 6, within cavity 166, body member160 includes three separate cavity dividing members including a centralor first dividing member 180 and second and third lateral dividingmembers collectively identified by numeral 182. As its label implies,central dividing member 180 is positioned centrally within cavity 166and generally divides the cavity into two separate channels. Centraldividing member 180, in the illustrated embodiment, extends such thatits distal end is flush with surface 164 of body member 160. Inaddition, central dividing member 180 extends all the way to a first end184 of cavity 166 but stops short of a second end 186 of the cavity, thesecond end 186 being opposite first end 184.

[0129] Each of the second and third dividing members 182 is positionedon a different side of central member 180 and each stops short of boththe first cavity end 184 and the second cavity end 186. In addition,each of dividing members 182 forms a plurality of openings so thatliquid flowing on either side of the member can pass to the oppositeside of the member. Exemplary openings are identified by numeral 190 inFIG. 3. Like central member 180, in the illustrated embodiment, each ofthe second and third lateral members 182 extends such that its distalend is flush with surface 164 of body member 160.

[0130] With openings 190 formed in each of dividing members 182, whatremains of members 182 includes protuberances 290 that essentially breakup the flow of coolant through the two channels formed within the cavity166 as described in greater detail below. In the illustrated embodimentthe protuberances 290 are essentially equi-spaced along the channellengths.

[0131] At the first end 144 of the sink member, in the illustratedembodiment, body member 160 forms an inlet or receiving chamber 192 andfirst and second nozzle passageways 194 and 196, respectively. Inletchamber 192 is formed between end 144 and cavity 166 and is connected tocavity 166 on one side of central member 180 by first nozzle passageway194 and is connected to cavity 166 on the other side of central dividingmember 180 by second nozzle passageway 196. Inlet chamber 192 has arelatively large cross-sectional area when compared to either of nozzlepassageways 194 and 196 so that inlet chamber 192 can act as a reservoirfor providing liquid under pressure to cavity 166 through the nozzlepassageways 194 and 196. In the illustrated embodiment, each of thesecond and third lateral dividing members 182 is positioned such thatthe protuberance 290 closest to the inlet nozzle passageway 194 or 196is aligned therewith. At second end 146 of body member 160, body member160 forms a channel extension 210 having a width dimension that is lessthan the cavity width W4.

[0132] Body member 160 can be formed in any manner known in the art. Onemethod for providing member 160 includes providing the member withoutcavity 166 and scraping metal out of surface 164 to provide a suitablecavity. Another method may be to form body member 160 in a mold. Othermanufacturing processes are contemplated.

[0133] Cover member 162 is a substantially planar and rigid rectilinearmember having a shape which mirrors the shape of surface 164. Member 162forms an inlet opening 200 at a first end 204 and an outlet opening 202at a second 206. The inlet 200 and outlet 202 are formed such that, whencover member 162 is secured to surface 164, inlet 200 opens into inletchannel 192 and outlet 202 opens into extension 210.

[0134] To secure cover member 162 in a hermetically sealed manner tosurface 164, any method known in the industry can be employed. Onemethod which has been shown to be particularly useful in providing ahermetic seal between cover member 162 and body member 160 has been touse a vacuum brazing technique where a bead of brazing material isprovided along surface 164 of body member 160, cover member 162 isprovided on surface 164 with the brazing bead sandwiched between members162 and 160 and then the component assembly is subjected to extremelyhigh heat thereby causing a brazing function to occur. Other securingmethods are contemplated.

[0135] As illustrated, each of body member 160 and cover member 162 forma plurality of apertures (not separately numbered) for receivingmechanical components such as screws, bolts, etc., for mounting devicepackages 90, 92, 94 and 96 and, perhaps, other electronic devices, tothe sink member 102. In addition, body member 160 and/or cover member162 may include other apertures for mounting other converter components(e.g., the bracket described below) to sink member 102 and/or to mountthe sink member 102 within a converter housing for support.

[0136] Referring once again to FIG. 2 and also to FIG. 5, capacitors 50are standard types of capacitors and, to that end, generally include acylindrical body member having a first end 220 and a second end 222opposite the first end 220 where terminals 224 and 226 extend from eachfirst end 220 and a heat conducting extension 228 (see FIG. 5) extendscentrally from each second end 222. The heat conducting extensions 228,as the label implies, conducts most of the heat from the central core ofthe capacitor. Each capacitor 50 has a length dimension L1 whichseparates the first and second ends 220 and 222.

[0137] Referring now to FIGS. 2, 4 and 5, bracket member 104 is, in atleast one embodiment, formed of a heat conducting, rigid material suchas aluminum or copper. Bracket member 104 includes a proximal member230, an intermediate member 232 and a distal member 234. Proximal member230 includes a flat elongated member which has a length substantiallyequal to the length of sink member 102. Proximal member 230 forms aplurality of mounting apertures along its length which align withsimilar apertures (not illustrated) in the surface 142 formed by covermember 162 (see again FIG. 3).

[0138] Intermediate member 232 forms a 90° angle with proximal member230 and extends from one of the long edges of member 230. Similarly,distal member 234 extends from the long edge of intermediate member 232opposite the edge linked to proximal member 230 and forms a 90° anglewith intermediate member 232. The 90° angle formed between intermediatemember 232 and distal member 234 is in the direction opposite the angleformed between proximal member 230 and intermediate member 232 so thatdistal member 234 extends, generally, in a direction opposite thedirection in which proximal member 230 extends. Although notillustrated, distal member 234 forms a plurality of apertures throughwhich the heat dissipating capacitor extension members 228 extend formounting the capacitors 50 thereto. In the illustrated embodiment,distal member 234 forms two rows of substantially equi-spaced aperturesfor receiving the capacitors 50 and arranging the capacitors 50 in twoseparate rows.

[0139] Referring again to FIGS. 2, 4 and 5, laminated bus bar 106includes a substantially planar member having a general shape similar tothe shape of distal member 134. Although not illustrated, it should beappreciated by one of ordinary skill in the art that laminated bus bar106 includes several metallic conducting layers where adjacent layersare separated by insulating layers and wherein different ones of aconducting layers are linked to connecting terminals along one edge ofthe bus bar. Exemplary connecting terminals are identified by numeral240 in FIGS. 2 and 4.

[0140] In addition, although not illustrated, separate vias are providedin an underside of bus bar 106 which facilitate connection of particularpoints and particular conducting laminations within bar 106 to thecapacitors juxtaposed thereunder when the converter assembly isconfigured. More specifically, referring to FIGS. 1a and 1 b once again,bus bar 106 links various emitters and collectors of the switchingdevices 30-41 and 61-72 to the positive and negative DC buses separatedby the capacitors 50 as illustrated. Thus, for example, bus bar 106links the collector of switch 30 to the positive DC bus 18, the emitterof switch 36 to the negative DC bus, the collector of switch 31 to thepositive DC bus 18, the emitter of switch 37 to the negative DC bus 20,and so on.

[0141] It should be appreciated that bus bar 106 can have an extremelysimple and hence minimally expensive construction when used with a sinkand switching device configuration that aligns all intra-converterconnection terminals in a single line and in a single connection plane.Here only a minimal number of laminate layers are required and no viasare required to link to the switching devices as connection terminals240 are within the same plane as the device terminals.

[0142] With the converter components configured as described above, aparticularly advantageous converter assembly can be assembled asfollows. First, after the cover member 62 has been hermetically sealedto body member 160, device packages 90, 92, 94 and 96 are mounted tomounting surface 140 of sink member 102 so as to form a single devicerow as illustrated best in FIG. 4. Next, bracket member 104 is securedto surface 142 of cover member 102 so that intermediate member 232generally extends away from sink member 102 and so that distal member234 also extends generally away from sink member 102. Capacitors 50 arenext mounted to distal member 234 with their extending heat dissipatingextensions 228 passing through apertures in member 234 and so that thecapacitors 50 form two capacitive rows as illustrated in FIGS. 2 and 5.

[0143] At this point, it should be appreciated that, when bracket member104 is suitably dimensioned, the connection terminals 224 and 226 thatextend from the first ends 220 of the capacitors 50 should be within thesame connection plane as the intra-converter connection terminalsextending toward the capacitors 50 from each of device packages 90, 92,94 and 96. To this end, the bracket member 232 should be chosen suchthat the length dimension L2 of intermediate member 232, when added tothe sink member thickness T3 and the device thickness T1 (notillustrated), essentially equals the capacitor length L1. When any ofthe sink member 102, the capacitors 50 or the device packages (e.g., 90)are replaced by other components having different dimensions, thedifferently dimensioned components can be accommodated and the capacitorand device package connecting terminals can be kept within the sameplane by selecting a bracket member 104 having a different intermediatemember 232 length dimension L2. Thus, the bracket-sink member assemblyrenders the sink member extremely versatile when compared to previoussink configurations that required multi-plane serpentine coolant paths.

[0144] With the capacitor connecting terminals and the intra-converterterminals extending from the device packages within the same connectionplane, planar and relatively simple bus bar 106 is attached to thecapacitor and intra-converter terminals thereby linking the variousterminals to the positive and negative buses 18 and 20 in the fashionillustrated in FIGS. 1a and 1 b above.

[0145] Continuing, the input and output bus bars 12′, 14′, 16′, 24′, 26′and 28′ are next linked to the inter-converter connection terminals asillustrated in FIG. 4 and to link the emitters and capacitors of theswitching devices 30-41 and 61-72 at the common nodes (e.g., 46, 80,etc.) as illustrated in FIGS. 1a and 1 b.

[0146] Referring now to FIG. 5, when all of the components describedabove are secured together in the manner taught, an extremely compactconverter assembly that requires a relatively small volume isconfigured. In fact, as illustrated, a space 280 is formed adjacentsurface 142 of cover member 162 and adjacent intermediate member 232where additional components such as the components required to configurecontroller 22 can be mounted. In some embodiments, at least some of thecomponents of controller 22 will be mounted within cooling space 280 toa second mounting surface formed by surface 142 of cover member 162 sothat the mounted components dissipate heat into sink member 102.

[0147] Referring again to FIGS. 3 and 6, with cover member 162 securedto surface 164, when liquid is pumped through inlet 200 and into inletchamber 192, after chamber 192 fills with liquid, the liquid is forcedthrough each of restricted nozzle inlets 194 and 196 into opposite sidesof cavity 166 (i.e., into different halves of cavity 166 where thehalves are separated by central dividing member 180). Because the nozzlepassageways 194 and 196 are restricted, the coolant is forcedtherethrough under pressure which should overcome any pressuredifferential that exists within the opposite sides of cavity 166. As theliquid passes through cavity 166 on its way to and out outlet 202, theliquid heats up between first channel end 184 and second channel end 186and a phase change occurs wherein at least a portion of the liquid, asheat is absorbed, changes from the liquid state the state gas therebyforming bubbles within cavity 166.

[0148] Protuberances 290 cause excessive amounts of turbulence withincavity 166 as the protuberances 290 redirect liquid along randomtrajectories within the channels. The excessive turbulence within cavity166 is such that essentially no gas pockets form on the internalsurfaces of the cavity 166 or the portion of cover member 162 enclosingcavity 166. In embodiments where sink member 102 is vertically aligned,bubbles that form within the cavity float upward under the force ofliquid flow and the force of their own buoyancy. The bubbles proceed outthe outlet 202 and are thereafter condensed by the cooling systemattached thereto as the refrigerant is cooled.

[0149] In FIG. 6, as indicated above, cavity 166 has a width dimensionW4 that is, at least in one embodiment, similar to the width dimensionW2 of the heat generating portion of device or package surface 122 (seealso FIG. 3). Where dimension W2 is smaller, it is contemplated that thedual channel aspect of cavity 166 may not be required. For example,assume dimension W2 is half the dimension illustrated in the figures. Inthis case, the cavity 166 may be made approximately half the illustrateddimension and hence central member 180 may not be needed.

[0150] Experiments have shown that if width dimension W4 is too largeand no dividers 180 are provided along the cavity length L4, theturbulence generated by the protuberances 290 is substantially reduced.Thus, for instance, assume member 180 were removed from cavity 166. Inthis case much of the coolant pumped into cavity 166 through passageways194 and 196 would pass relatively calmly through to the outlet end 186of cavity 166. The maximum width of each channel formed within cavity166 is going to be a function of various factors including cavity depth,coolant employed, coolant pressure, the quantum of heat generated bydevice packages mounted to the sink, etc.

[0151] It should be appreciated that the protuberances 290 and divider180 within cavity 166 are specifically provided to increase channelturbulence to a level that eliminates gas pockets on channel surfaces.Without gas pockets on the channel surfaces, refrigerant/coolant is insubstantially full contact with all channel surfaces and the temperaturedifferential between the first and second channel ends 184 and 186 issubstantially reduced. The smaller channel temperature differentialmeans that devices mounted to sink member 102 have more similaroperating characteristics as desired.

[0152] Referring now to FIG. 9 a method 300 according to one aspect ofthe present invention is illustrated. Here, at block 302, a body member160 (see again FIG. 3) having a limited width dimension W3 and a lengthL5 is provided where the limited width dimension is substantiallysimilar to or identical to the width dimension W1 of the devices to beattached thereto. At block 304, a cavity is formed in a first surface ofthe body member 160 that extends substantially along the entire lengthdimension L5. The cavity is illustrated as 166 in FIG. 3. At block 306,a cover member 162 is provided that is consistent with the teachingsabove. At block 308 an inlet is formed in one of the body member and thecover member. At block 310 an outlet is formed in one of the body memberand the cover member. As above, the inlet and outlet formed should openinto opposite ends of the cavity or channel 166. At block 312, the covermember 162 is hermetically sealed in any manner known in the art to thebody member 160 thereby providing an enclosed channel having only asingle inlet and a single outlet at opposite ends. Continuing, at block314, power switching devices for packages 90, 92, 94 and 96 are mountedto the second or mounting surface with their dissipating widthdimensions substantially parallel to the receiving width dimension W3 ofthe heat sink.

[0153] While the system described above includes four separate powerswitching device modules, two modules configured to provided a rectifierand two modules configured to provide an inverter, it should beappreciated that other applications may require more or less powercapability. Where less power is required, if suitable, only two powerswitching device modules may be required. In this case, the heat sinkmember 102 may be made relatively shorter so as to, generally,accommodate the two modules. Where more power capability is required, inat least some applications, because a temperature differential may occurif an excessive number of modules are aligned along a relatively longlength heat sink member, if will be desirable to provide more than oneheat sink member like member 102. In this case, two or more sink membersmay be aligned essentially end to end with the switching device moduleson each of the members aligned in a single line or, in the alternative,two sink members may be vertically aligned so as to be substantiallyparallel to each other. In either of these two cases, a single bracketmember and a single laminated bus bar may be configured to link all ofthe module switching devices and capacitors together thereby forming asuitable converter topology.

[0154] Referring now to FIGS. 10a, 10 b and 10 c, a relatively highpower embodiment of the present invention will be described in thecontext of an exemplary motor control system 348 including a rectifierassembly generally illustrated in FIG. 10a which feeds a capacitor bankin FIG. 10b and an inverter assembly generally illustrated in FIG. 10cwhere each of the rectifier and inverter are controlled by a controller350. As known in the controls industry, the rectifier (FIG. 10a)receives three-phase AC voltage on input lines 352, 354, and 356 andconverts that three-phase voltage to a DC potential across positive andnegative DC buses 360 and 362, respectively. The DC buses 360 and 362generally feed the capacitive bank (FIG. 10b) and the inverterconfiguration (see again FIG. 10c) which converts the DC potential tothree-phase AC voltage waveforms that are provided to a three-phase loadvia first, second and third inverter output lines 468, 470 and 472,respectively.

[0155] The rectifier assembly in FIG. 10a includes first through fourthseparate power switching device modules 368, 370, 372 and 374 where eachof the switching device modules includes six separate power switchingdevices. For example, module 368 includes switching devices 376-381,module 370 includes switching devices 382-387 and so on. First andsecond switching devices in module 372 are identified by numerals 388and 390 and first and second switching devices in module 374 areidentified by numerals 391 and 392, respectively. The switching devicesare arranged between the positive and negative DC buses 360 and 362,respectively, to provide 12 separate rectifier legs. Each rectifier legincludes a pair of series connected switching devices that traverse thedistance between the positive and negative DC buses 360 and 362,respectively. For example, a first rectifier leg includes an upperswitch 376 and a lower switch 377 that are in series between positivebus 360 and negative bus 362, a second rectifier leg includes an upperswitch 378 and a lower switch 379 that are in series between buses 360and 362, and so on. Each power switching device module 368, 370, 372 and374 includes first, second and third rectifier legs or switch pairs.Hereinafter, the labels first, second and third switch pairs will beused to refer the left most, center and right most switch pairs on eachof modules 368, 370, 372 and 374. For example, referring still to FIG.10a, switches 376 and 377 will be referred to as the first switch pairof module 368, switches 378 and 379 will be referred to as the secondswitch pair of module 368 and switches 380 and 381 will be referred toas the third switch pair of module 368. Similarly, switch pairs 382 and383, 384 and 385 and 386 and 387 will be referred to as the first,second and third switch pairs of module 370, and so on.

[0156] The nodes between switches in each device pair are referred to ascommon nodes (i.e., a node that is common to the switch pair). A commonnode between switches 376 and 377 is identified by numeral 400, a commonnode between switches 378 and 379 is identified by numeral 408 and thecommon node between switches 380 and 381 is identified by numeral 401.The common nodes for the first, second and third switch pairs in module370 are identified by numerals 402, 410 and 403, respectively, thecommon nodes for the first, second and third switch pairs in module 372are identified by numerals 404, 412 and 405 and the common nodes for thefirst, second and third switch pairs in module 374 are identified bynumerals 406, 414 and 407, respectively.

[0157] Each of input lines 352, 354, and 356 is separately linked tofour different common nodes where each node is from a different one ofthe modules and no common node is linked to more than one input line.For example, as illustrated, line 352 is linked to common nodes 400,402, 404 and 406. In a similar fashion, input line 354 is linked tocommon nodes 408, 410, 412 and 414 while input line 356 is linked tocommon nodes 401, 403, 405 and 407. As described above with respect toFIGS. 1a and 1 b, switch emitters, collectors and gates are identifiedvia E, C and G labels, respectively, in FIG. 10a (as well as in FIG. 10cdescribed below).

[0158] Control bus 358, which represents a plurality of differentcontrol lines, links controller 350 separately to each one of therectifier switches for independent control. Controller 350 controls wheneach of the switches turns on and when each of the switches turns off.Switch pairs having their common nodes linked to the same input line arecontrolled in identical fashion by controller 350.

[0159] Referring to FIG. 10b, the rectifier configuration also includesfirst and second sets or pluralities of capacitors 661, 663 linkedbetween the positive and negative DC buses 360 and 362. Morespecifically, the capacitors include a first upper set 661 linkedbetween positive DC bus 360 and a neutral bus 361 and a second lower set663 linked between negative DC bus 362 and neutral bus 361.

[0160] Referring now to FIG. 10c, the inverter configurationillustrated, like the rectifier configuration of FIG. 10a, includesfirst through fourth separate power switching device modules 420, 422,424, and 426 (also, sometimes referred to fifth through eighth modules,respectively) where each module includes six separate power switchingdevices arranged in first, second and third device pairs between thepositive and negative DC buses 360 and 362, respectively. For example,module 420 includes a first switch pair including an upper switch 428and a lower switch 429 arranged between buses 360 and 362, a secondswitch pair includes an upper switch 430 and a lower switch 431 and athird switch pair includes switches 432 and a lower switch 433. Theswitches that comprise the first switch pair in module 422 areseparately identified by numerals 434 and 435, the switches thatcomprise the first switch pair in module 424 are separately identifiedby numerals 440 and 441 while the switches that comprise the firstswitch pair of module 426 are identified by numeral 446 and 447. As inthe case of the rectifier configuration, hereinafter, unless indicatedotherwise, the left most, center and right most switch pairs in each ofmodules 420, 422, 424 and 426 as illustrated in FIG. 10c will bereferred to as the first, second and third switch pairs of therespective modules.

[0161] In FIG. 10c, the common nodes corresponding to the first switchpairs of each of modules 420, 422, 424, and 426 are identified bynumerals 450, 452, 454 and 456. Similarly, the common nodescorresponding to the second switch pairs in each of the modules 420,422, 424, and 426 are identified by numerals 458, 460, 462 and 464 whilethe common nodes corresponding to the third switch pairs in each of themodules 420, 422, 424, and 426 are identified by numerals 471, 473, 475and 477.

[0162] In the illustrated embodiment, each output line 468, 470 and 472is linked to four separate common nodes from different modules. Forexample, output line 472 is linked to each first switch pair common nodeincluding nodes 450, 452, 454 and 456. Similarly, output line 470 islinked to each second switch pair common node including nodes 458, 460,462 and 464 while line 468 is linked to each third switch pair commonnode 471, 473, 475 and 477.

[0163] Control bus 358 from controller 350 is linked to each of theinverter switches to independently control the turn on and turn off ofthose switches. As in the case of the rectifier switches illustrated inFIG. 10a, controller 350 controls the switches of the inverterconfiguration that have common nodes linked to the same output line inidentical fashions.

[0164] Referring now to FIG. 11, an exploded perspective view of anexemplary rectifier/inverter configuration 500 that implements thedesign of FIGS. 10a-10 c is illustrated. Configuration 500 includesfirst and second heat sink member 502 and 503, the eight power switchingdevice modules 368, 370, 372, 374, 420, 422, 424 and 426 brieflydescribed above, a bracket member 514, a plurality of capacitorscollectively identified by numeral 516, a laminated bus bar 517 and aplurality of input and output bus bars identified by numerals 352, 354,356, 468, 470 and 472.

[0165] Each of modules 368, 370, 372, 374, 420, 422, 424 and 426 issimilarly constructed and, generally, is constructed in a manner similarto the switch packet 90 described above. Thus, each of the modules has alength dimension, a width dimension and a thickness dimension (see againFIGS. 3 and 5) and also has first and second linking edges that face inopposite directions. As in the case of package or module 90, each of themodules in FIG. 11 includes six switching devices arranged in a singlerow relationship where first and second sub-sets of switching deviceemitters and collectors extend from opposites sides of the module andare generally separated by the device width. As above, each of themodules in FIG. 11 is designed so that all the emitter and collectorterminals extend from the module housing within a single connectionplane.

[0166] Switching device connection terminals that are linked to any ofbus bars 352, 354, 356, 468, 477 or 472 are referred to asinter-converter terminals because after configuration 500 is assembled,those terminals are connected through their respective bus bars tocomponents outside the converter configuration. Similarly, any devicepackage terminals linked to laminated bus bar 517 after configuration500 is assembled are referred to herein as intra-converter terminals asthose terminals are linked to other components within the converterassembly.

[0167] Referring still to FIG. 11, after exemplary configuration 500 isassembled, all of the inter-converter terminals of each module mountedto sink member 502 extend in the same direction and from a line tofacilitate easy linkage to bus bars and all of the intra-converterconnection terminals of each module mounted to sink member 502 extend inthe opposite direction and from a line to facilitate easy linkage to busbar 517 linking tabs. Similarly, after assembly, the inter-converter andintra-converter connection terminals of modules mounted to sink member503 extend in opposite directions and form inter-converter andintra-converter connection terminal lines to facilitate easy linking toassociated bus bars and the bus bar 517 linking tabs, respectively.

[0168] Referring still to FIG. 11 and also to FIG. 13, in at lease someembodiments of the present invention, configuration 500 components arejuxtaposed such that the intra-converter terminals of the modulesmounted to first sink member 502 face the intra-converter terminals thatextend from the modules mounted to second sink member 503 while theinter-converter connection terminals of the modules mounted to firstsink member 502 extend in an opposite direction from the inter-converterconnection terminals of modules mounted to second heat sink member 503.This limitation makes possible a converter configuration where a singleand relatively simple laminated bus bar can be used to link theintra-converter terminals as illustrated in FIGS. 10a, 10 c, 11, 12 and13.

[0169] Control ports (see 701 in FIG. 13) are provided on a top surfaceof each power switching device module, (e.g., 368, 370, etc.) tofacilitate linking of control bus 358 to the devices provided within themodules. Modules 368, 370, 372, 374, 420, 422, 424, and 426 aremechanically mounted to mounting surfaces of heat sink members 502 and503 in the manner described above with respect to FIGS. 2 and 3 (e.g.,via bolts or the like received in mounting apertures) and therefore willnot be described again here in detail.

[0170] Referring still to FIG. 11, consistent with the linkage patternillustrated in FIG. 10a, each of the input bus bars 352, 354 and 356 isa steel bar that has a shape such that the bar is connectable to aseparate switching device pair in each of rectifier modules 368, 370,372 and 374. More specifically, bus bar 352 includes an elongated spinemember 413 and four separate rib members that extend therefrom, aseparate rib member corresponding to each of rectifier modules 368, 370,372 and 374. In FIG. 11, the rib members linked to spine member 413 havebeen labeled with numbers corresponding to the common nodes of the firstswitching device pairs of each of the rectifier modules in FIG. 10a tohighlight the linking relationship between the ribs and thecorresponding common nodes. For example, the first rib extending fromspine member 413 in FIG. 11 that links to common node 400 in FIG. 10a issimilarly identified by numeral 400, the second rib extending from spinemember 413 that links to common node 402 in FIG. 10a is similarlyidentified by numeral 402 and the third and fourth extending ribs thatlink to common nodes 404 and 406 in FIG. 10a are similarly labeled 404and 406, respectively. A linking tab 591 extends from spine member 413generally in a direction opposite the direction of ribs 400, 402, 404and 406.

[0171] Second input bus bar 354, like first bar 352, includes a spinemember 411 and first through fourth rib members 408, 410, 412 an 414,respectively, that extend to one side thereof and that are juxtaposedsuch that, upon assembly, they align with and are linkable to commonnodes 408, 410, 412 and 414 of the second switch pairs of each ofmodules 368, 370, 372 and 374 as illustrated. A linking extension member593 extends in a direction opposite the ribs from spine member 411.

[0172] Third input bus bar 356 includes a spine member 409 and four ribmembers 401, 403, 405 and 407 that extend to one side thereof and thatare juxtaposed such that, upon assembly, they align with and arelinkable to similarly numbered common nodes 401, 403, 405 and 407 inFIG. 10a that correspond to the third switching device pairs of each ofmodules 368, 370, 372 and 374. An input linking extension 595 extendsfrom spine member 409 in a direction opposite the rib members.

[0173] Referring still to FIG. 11 and also to FIG. 10c, like input busbars 352, 354 and 356, output bus bars 468, 470 and 472 each include aspine, four rib members and an oppositely extending extension member forlinking to an associated output line. More specifically, bus bar 472includes spine member 540, first through fourth rib members 450, 452,454, and 456 that extend in the same direction from, and that are spacedalong spine member 540, and extension member 610 that extends in adirection opposite the rib members from spine member 540. Bus bar 470includes spine member 479, four spaced apart and similarly directed ribmembers 458, 460, 462 and 464 and extension member 612 and bus bar 468includes spine member 481, four rib members 471, 473, 475 and 477 and anoppositely extending extension member 614. Rib members 450, 452, 454 and456 are juxtaposed and spaced apart such that, upon assembly, the ribmembers align with, and are linkable to, the common nodes of each firstswitch pair in modules 420, 422, 424, and 426, respectively. Tohighlight the linkage pattern, rib members 450, 452, 454, 456 areidentified by the same numbers as the nodes to which they are linked inFIG. 10c. Similarly, rib members 458, 460, 462, 464, 471, 473, 475 and477 are juxtaposed and spaced apart such that, upon assembly, the ribmembers align with, and are linkable to, similarly numbered common nodesin FIG. 10c.

[0174] Referring again to FIG. 11 and also, again, to FIGS. 3 and 4,each of heat sink members 502 and 503 is similar to heat sink member 102described in detail above and therefore, in the interest of simplifyingthis explanation, will not be described here in detail. However, somesimple description of members 502 and 503 will be helpful in explainingrelative juxtapositions of assembly 500 components. To this end, sinkmember 502 includes a mounting surface 530, first and second lateralsurfaces 534 and 532, respectively, and first and second lateral edges538 and 536, respectively. Edge 538 is formed by surfaces 530 and 534while edge 536 is formed by surfaces 530 and 532. Similarly, member 503includes a mounting surface 531, first and second lateral surfaces 535and 533 and first and second lateral edges 539 and 537. First lateraledge 539 is formed by the intersection of surfaces 531 and 535 whilesecond lateral edge 537 is formed by intersection of surface 531 withsurface 533.

[0175] Referring now to FIGS. 11, 12 and 13, bracket member 514 is, inthe illustrated embodiment, formed of a heat conducting rigid materialsuch as aluminum or copper. Member 514 includes first and secondproximal or lateral end members 620 and 628, two intermediate members622 and 626 and a central member 624. Each of first and second endmembers 620 and 626 includes a flat elongated member which has a lengthsubstantially equal to the length of one of heat sink members 502 or503. Each of members 620 and 628 forms a plurality of mounting aperturesalong its length which align with similar apertures (not illustrated) insurfaces of sink members 502 and 502 opposite mounting surfaces 530 and531, respectively.

[0176] Intermediate members 622 and 626 form 900 angles with end members620 and 628, respectively, and extend from one of the long edges of thecorresponding end members 620 and 628. Central member 624 forms abracket mounting surface 630 that is, in the illustrated embodiment,parallel to members 620 and 628 and forms a plurality of apertures (notillustrated) for receiving heat dissipating extension members of each ofcapacitors 516. In the illustrated embodiment, central member 624 formsfour rows of substantially equispaced apertures for receiving capacitors516 and arranging the capacitors 516 in two separate rows.

[0177] Referring still to FIGS. 11, 12 and 13, laminated bus bar 517includes a substantially planar member having a shape similar to theshape of central member 624. Referring also to FIG. 17, laminated bar517 includes several metallic conducting layers where adjacent layersare separated by insulating layers. In FIG. 17, laminated bar 517includes four insulating layers (left to right downward cross hatched)686, 687, 690 and 681, a positive DC bus layer 360, a negative DC buslayer 362 and a neutral bus layer 361. Also shown in FIG. 17 arepositive and negative vias and extension terminals 455 and 457 describedin greater detail below. Positive bus 360 is insulated between layers686 and 688, negative bus 362 is insulated between layers 688 and 690and neutral bus 361 is insulated by layers 690 and 681. Hereafter,insulating layers 681 and 686 will be referred to as first and secondexternal layers, respectively, that form first and second externalsurfaces 703 and 705, respectively, that face in opposite directions.

[0178] Separate insulated via's (e.g., see 707) are provided in anunderside of bus bar 517 (e.g., through insulating layer 681) whichfacilitate connection of particular conducting laminations within busbar 517 to capacitor connection terminals juxtaposed thereunder when theconverter configuration is assembled.

[0179] Referring again to FIGS. 10a and 10 c, bus bar 517 links variousemitters and collectors of the switching devices in the power switchingdevice modules (e.g., 368, 420, etc.) to the positive and negative DCbuses 360 and 362, respectively. For instance, laminated bar 517 linksthe collector of switch 376 to positive DC bus 360, the emitter ofswitch 377 to the negative DC bus, the collector of switch 378 to thepositive DC bus, the emitter of switch 379 to the negative DC bus, andso on.

[0180] Referring again to FIGS. 11 and 13, in addition to the componentsdescribed above, laminated bar 517 also includes linking constructs,linkages or tabs 623, 634, that extend laterally from first and secondlinking edges 708 and 710, respectively. The linking edges 708 and 710are straight and, in the illustrated embodiment, are parallel andcomprise opposite edges of bar 517. Because edges 708 and 710 arestraight, the linking tabs 632, 634 form first and second linking linesalong the edges. First and second subsets of tabs 632, 634 are linked tothe positive and negative DC bus layers 360 and 362. The tabs from thefirst and second sets are arranged and juxtaposed such that, uponassembly, the tabs align with, and are linkable to, intra-converterconnection terminals on modules 368, 370, 372, 374, 420, 422, 424 and426 to link switching devices in the modules to the positive andnegative DC buses as illustrated in FIGS. 10a and 10 c. Thus, in FIGS.10a and 10 c, laminate bar 517 links all upper switching devices (i.e.,devices illustrated above associated common nodes) to positive DC bus360 and links all lower switching devices (i.e., devices illustratedbelow associated common nodes) to negative DC bus 362.

[0181] As in the embodiment described above with respect to FIGS. 2, 3and 4, it should be appreciated that bus bar 517 has an extremely simpleand hence minimally expensive construction when used with a sink andswitching device configuration that aligns all intra-converterconnection terminals in two lines and in a single connection plane wherethe intra-converter connection terminals are located on opposite sidesand on opposite edges of the laminated bar 517. Here, despite the largenumber of power switching devices and high power capabilities, only aminimal number of laminate layers are required and no via's are requiredto link the switching devices because the connection terminals are allwithin a single plane and are located at laminate edges.

[0182] It should also be appreciated that, when bracket member 514 issuitably dimensioned, the connection terminals that extend from thecapacitors 516 will be within the same connection plane as theintra-converter connection terminals extending toward the capacitors 516from each of modules 368, 370, 372, 374, 420, 422, 424 and 426. Here,bracket member 514 should be designed such that the length dimensions ofthe intermediate members 622 and 626, when added to the sink memberthickness (see again T3 in FIG. 5) and the module thickness (notillustrated) is essentially equal to the capacitor length L1 (see againFIG. 5).

[0183] In at least some embodiments it is important that linking edges708 and 710 of laminated bar 517 face in opposite directions and areparallel. In this regard, as described above, to operate mostefficiently, liquid cooled sink members 502 and 503 have to bepositioned such that their internal spaces or channels are generallyvertically aligned and so that channel inlets are below channel outletson the same sink member. Thus, by configuring bar 517 with oppositelyfacing parallel linking edges 708 and 710, the requirement that bothsinks 502 and 503 be aligned with their lengths vertical can be met.Nevertheless, other configurations are contemplated where the linkingedges may include other than parallel edges.

[0184] With the capacitor connection terminals and the intra-converterterminals extending from the device modules within the same connectionplane, planar and relatively simple bus bar 517 is attached to thecapacitor and intra-converter terminals thereby linking the variousterminals to the positive and negative buses 360 and 362 in the fashionillustrated in FIGS. 10a and 10 c above.

[0185] Next, the input and output bus bars 352, 354, 356, 472, 474 and476 are linked to the inter-converter connection terminals asillustrated in FIGS. 11 and 13 to link the emitters and collectors ofthe switching devices at the common nodes as illustrated in FIGS. 10aand 10 c.

[0186] Once configuration 500 has been assembled, configuration 500 ismounted within the space provided for by a specific application suchthat the inlet apertures or openings into the internal spaces formed bysink members 502 and 503 are below the outlets corresponding to thosespaces, and generally, so that sinks 502 and 503 are substantiallyvertically aligned. Thus, when cooling liquid is pumped into the inletsat the bottoms of sink members 502 and 503, the cooling liquid movesupward within the internally formed channels and exits the outletsthereabove after absorbing sink and module heat.

[0187] Referring once again to FIGS. 10b, 11, 12, 13 and 17, accordingto an additional aspect of the present invention, positive and negativeDC bus tabs or external linkage terminals 455 and 457, respectively, arelinked to the positive and negative DC buses 360 and 362, respectively,of the laminated bus bar 517. As best seen in FIG. 17, first and secondvias 692 and 694 are formed in laminated bar 517 through second surface705 that open into or terminate at the positive and negative DC buses360 and 362, respectively. Via 692 opens through second externalinsulating layer 686 while via 694 opens through layer 686, DC bus layer360 and insulating layer 688. The lateral internal walls of via 694 arelayered with an insulator 696 to avoid a short between the positive andnegative DC buses 360 and 362. Terminals 455 and 457 extend through vias692 and 694, link to positive and negative DC bus layers 360 and 362 andhave exposed distal ends linkable to either a DC source or a loadrequiring DC power. Terminals 455 and 457, in the illustratedembodiment, extend in a perpendicular direction from the top surface oflaminated bar 512 although other extending directions and configurationsare contemplated.

[0188] With DC bus tabs 455 and 457 extending as illustrated, theconfiguration described above can be linked to power sources and loadsin several different ways and can be controlled by controller 350 invarious ways to facilitate several types of power conversion. Forexample, as described above, a three-phase source can be linked to inputlines 352, 354, and 356 and a three-phase load can be linked to outputlines 468, 470 and 472 and controller 350 can control modules 368, 370,372 and 374 to facilitate rectification while controlling modules 420,424, 424 and 426 to facilitate inversion to provide a three-phase AC/ACconverter. As another example, with a three-phase AC source linked toinput lines 352, 354 and 356, controller 350 may control modules 368,370, 372 and 374 to rectify the AC power and provide a DC source onpositive and negative DC buses 360 and 362 and thereby to positive andnegative DC terminals 455 and 457. Here, a load requiring DC voltage maybe linked to terminals 454 and 457 to receive power therefrom. Asanother example, a first three-phase source may be provided at inputlines 352, 354 and 356 while a second three-phase source is provided atlines 468, 4670 and 472 and controller 350 may be used to control all ofmodules 368, 370, 372, 374, 420, 422, 424 and 426 to facilitaterectification thereby providing a higher DC power at tabs 455 and 457.

[0189] In yet another example, a separate DC source that is notillustrated may be linked to terminals 455 and 457, a first AC load maybe linked to lines 352, 354 and 356, the second three-phase AC load maybe linked to lines 468, 470 and 472 and controller 350 may controlmodules 368, 370, 372 and 374 as well as modules 420, 422, 424 and 426to provide DC/AC power conversion. Thus, it the positive and negative DCterminals 455 and 457 linked to the DC buses formed by laminated bar 517appreciably increase the versatility of the relatively complex and largescale conversion configuration illustrated in FIGS. 10a through 13.

[0190] Referring still to FIG. 11, by linking each of the input andoutput bus bars 352, 354, 356, 468, 470 and 472 to switch pairs in eachpower switching device module (e.g., 368, 370, etc.), the disparateoperating ranges of power switching devices in different modules averageand the overall conversion that occurs yields for better results.

[0191] The advantages of having input and output bus bars that arelinked to power switching devices in each of a plurality of differentpower switching device modules are obtainable in any configuration wherethe switches in two power switching device modules are to be controlledtogether to provide either rectification or inversion. For example,referring again to FIG. 1a and FIG. 2, input bus bars 12′, 14′ and 16′may each be shaped and configured such that input line 16 is linked tothe common nodes between switches 30 and 36, and switches 33 and 39,line 14 is linked to the common nodes switches 31 and 37 and switches 34and 40 and line 12 is linked to the common nodes between switches 32 and38 and switches 35 and 41, assuming switching devices 30, 31, 32, 36, 37and 38 are on a first power switching device module and devices 33, 34,35, 39, 40 and 41 are on a second power switching device module. Similarcomments are applicable to the inverter configuration illustrated inFIG. 1b where each of lines 24, 26 and 28 may be linked to first andsecond common nodes where the first and second common nodes correspondto switch pairs on different device modules.

[0192] Other bus bar configurations, in addition to those illustrated inFIGS. 11-13 above, are contemplated that provide similar multi-modularswitch averaging results. To this end, the components illustrated inFIG. 10a have been re-illustrated in FIG. 14, the only difference beingthe linking pattern between input lines 352, 354 and 356 and the switchpair common nodes. Specifically, comparing FIGS. 10a and 14, where anode linkage appearing in FIG. 10a has been altered in FIG. 14, thealtered linkage in FIG. 14 is identified by the same number used tolabel the linkage in FIG. 10a followed by a “′”. For example, commonnode 402 in FIG. 10a, which is linked to input line 352 has beenreplaced in FIG. 14 by similarly numbered common node 402′ (e.g., thecommon node of the third switch pair including switches 386 and 387 inmodule 370). Similarly, common node 406 linked to line 352 in FIG. 10ahas been replaced in FIG. 14 by similarly numbered common node 406′, thecommon node formed by the second switch pair in module 374.

[0193] In FIG. 14, first input line 352 is linked to common node 400corresponding to the first switching device pair in module 368, thecommon node 402′ corresponding to the third switching device pair inmodule 370, the common node 404 corresponding to the first switchingdevice pair in module 372 and common node 406′ corresponding to thesecond switching device pair in module 374. In addition, line 354 islinked to the common node 408 corresponding to the second switchingdevice pair in module 368, the common node 410 corresponding to thesecond switching device pair in module 370, the common node 412′corresponding to the third switching device pair in module 372 and thecommon node 414′ corresponding to the first switching device pair inmodule 374. In addition, third input line 356 is linked to the commonnode 401 corresponding to the third switching device pair in module 368,common node 403′ corresponding to the first switching device pair inmodule 370, common node 405′ corresponding to the second switchingdevice pair in module 372 and common node 407 corresponding to the thirdswitching device pair in module 374.

[0194] As illustrated in FIG. 14, each of the lines 352, 354 and 356 islinked to at least two adjacent common nodes where the adjacent commonnodes are in different power switching devices modules. For example,line 352 is linked to common node 402′ in module 370 and is also linkedto adjacent common node 404′ in module 372. Similarly, line 354 islinked to common node 412′ in module 372 and also to adjacent commonnode 414′ in module 374 while line 356 is linked to common node 401 inmodule 368 and to common node 403′ in module 370.

[0195] Referring now to FIG. 15 and also to FIG. 11, modules 368, 370,372 and 374 are re-illustrated in FIG. 15 and a second embodiment of busbars for linking to switching modules as shown in FIG. 14 isillustrated. Like bars 352, 354 and 356 in FIG. 11, bars 652, 654, 656each include a spine member 409, 411 and 413, respectively, and aplurality of rib members which extend in the same direction therefrom.However, instead of including four rib members, each of bars 352, 354and 356 includes only three rib members. For example, bar 352 includes afirst rib member 400, a second “double-wide” rib member identified byboth numerals 402′ and 404 and a third rib members identified by number406′.

[0196] Referring still to FIG. 15, bar 654 includes first rib member408, second rib member 410 and a third double-wide rib member identifiedby numerals 412′ and 414′ while third bar 656 includes a firstdouble-wide rib member identified by numerals 401 and 403′, a second ribmember 405′ and a third rib members 407′. In FIG. 15, bars 652, 654, 656are juxtaposed with respect to modules 368, 370, 372 and 374 such thatthe rib members of each bar are aligned with the intra-converterswitching device connection terminals that the bar links up with uponassembly of an associated converter configuration. To this end, it canbe seen that rib member 400 links to connection terminals 376E and 377C,rib member 408 links to connection terminals 378E and 379C, rib member401 links to connection terminals 380E and 381C and so on.

[0197] Each double-wide rib member links to a switching device pair ineach of two adjacent power switching device modules to perform thefunction of two of the rib members in the embodiment illustrated in FIG.11. For example, the double-wide rib member identified by numerals 402′and 404 straddles adjacent switch pairs in modules 370 and 372 toperform the linking functions corresponding to similarly numbered commonnodes 402′ and 404′ in FIG. 14. Similarly, double-wide rib memberidentified by numerals 412′ and 414′ straddles adjacent switching pairsin modules 372 and 374 to perform the linking function associated withsimilarly marked common nodes 412′ and 414′ in FIG. 14 while thedouble-wide rib member identified by numerals 401 and 403′ straddles theswitch pairs in modules 368 and 370 thereby performing the linkingfunction corresponding to common nodes 401 and 403′ in FIG. 14. Eachsingle wide rib (e.g., 400, 406, etc.) member in FIG. 15 is juxtaposedwith respect to an associated double-wide rib member such that thesingle-wide member links to a switch pair in a module other than amodule to which the associated double-wide rib member is linked. Forinstance, consistent with FIG. 14, rib member 400 is juxtaposed to linkto the first switch pair of module 368 while rib member 406′ isjuxtaposed to link to the third switch pair of module 374. Thus, theFIG. 15 bus bar configuration provides a function identical to thefunction of the bus bars illustrated in FIG. 11 where each bus bar 652,654 and 656 is linked to four separate switch pairs, each linked pairfrom a different one of modules 366, 370, 372 and 376.

[0198] Referring next to FIG. 16, a third bus bar embodiment isillustrated which includes bus bars 660, 662 and 664 that align withmodules 368-374 in FIG. 15 in a different fashion but that neverthelessperform functions identical to the bus bars illustrated in FIG. 11. Bars660, 662 and 664, each include a single spine member 409, 411 and 413,respectively. However, instead of including identical numbers of ribmembers, each of bus bars 660, 662 and 664 includes a different numberof rib members. Bus bar 660 includes first and second double-wide ribmembers 666 and 670, bar 662 includes first, second and third ribmembers 672, 674 and 676 where member 674 is double-wide and bar 664includes first through fourth single-wide rib members 678, 680, 682 and684, respectively. Rib member 666 is formed so as to straddle adjacentswitch pairs in modules 368 and 370 while rib member 670 is sized andpositioned with respect to rib member 666 such that, when rib member 666straddles the adjacent switch pairs in modules 368 and 370, rib member670 straddles adjacent switch pairs in modules 372 and 374. Second busbar rib member 674 is sized so as to straddle the connection terminalsof adjacent switch pairs in modules 370 and 372 while each of ribmembers 672 and 676 is sized and juxtaposed with respect to rib member674 such that, when rib member 674 straddles adjacent switch pairs inmodules 370 and 372, rib member 672 is linkable to one pair of switchingdevices in module 368 and rib member 676 is linkable to one pair ofswitching devices in module 374. Rib members 678, 680, 682 and 684 aresized and juxtaposed with respect to each other such that each of thoserib members links to a separate pair of switching devices in each ofmodules 368, 370, 372 and 374 that is not linked to one of the other ribmembers corresponding to either of bars 660 or 662. Thus, as in thecases of the bar configurations of FIGS. 11 and 15, each bar in FIG. 16links to a separate switch pair in each of modules 368, 370, 372 and374.

[0199] Although not illustrated, it should be appreciated that bus barssimilar to the bars illustrated in FIGS. 15 and 16 may be used toreplace bars 468, 470 and 472 in FIG. 11 to provide an identical switchaveraging function.

[0200] While various configurations and assemblies are described above,it should be appreciated that the present invention also contemplates amethod of configuring a simple yet extremely power conversionconfiguration that is relatively inexpensive to manufacture. To thisend, one exemplary method 730 is illustrated in FIG. 18. Referring toboth FIGS. 11 and 18, at block 732, first and second liquid cooled heatsink members 502 and 503 are provided having mounting surfaces 530 and531, respectively, and having length dimensions (not labeled in FIG. 11)where each mounting surface includes first and second oppositely facingedges. For example, sink member 502 includes oppositely facing first andsecond edges 538 and 536, respectively, while sink member 503 includesoppositely facing first and second edges 539 and 537, respectively.Referring also to FIGS. 3 and 6, each of sink members 502 and 503 formsan internal chamber that extends from an inlet to an outlet for guidingcooling liquid during sink operation.

[0201] At block 734, mounting bracket 514 is mounted between the sinkmembers such that the sink member length dimensions are substantiallyparallel (e.g., first edges 538 and 539 of sink members 502 and 503 aresubstantially parallel). At block 735, capacitors 516 are mounted to themounting surface 630 of bracket 514. At block 736, first and secondpluralities of switching devices are mounted to the first and secondsink member mounting surface 502 and 503 such that their intra-converterand inter-converter connection terminals are proximate the first andsecond edges of the respective mounting surfaces. For instance,referring once again to FIG. 11, the first plurality of switches mayinclude the switches that form modules 368, 370, 372 and 374 while thesecond plurality may include the switches that comprise modules 420,422, 424 and 426.

[0202] At block 740 laminated bus bar 517 is used to link theintra-converter connection terminals and the capacitors to the positiveand negative DC buses within the laminate bus bar to form the convertertopology desired. Next, at block 742, controller 350, a source and aload are linked to the topology. This linking step at block 742 maycomprise providing and linking input and output bus bars as illustratedin FIG. 11 and then linking the source and the load lines to the busbars.

[0203] It should be understood that the methods and apparatusesdescribed above are only exemplary and do not limit the scope of theinvention, and that various modifications could be made by those skilledin the art that would fall under the scope of the invention. Forexample, while the sink member 102 is described as being formed of twocomponents other configurations are contemplated. In addition, theprotuberances 290 may take other forms that cause a suitable amount ofturbulence within the channel. For instance, in FIG. 7 anotherembodiment of the body member is illustrated. In FIG. 7 componentssimilar to the components of FIG. 6 are identified by identical numbersfollowed by an “a” qualifier. In FIG. 7, instead of providingsubstantially rectilinear protuberances as in FIG. 6, triangularprotuberances 290 a are provided on either side of member 280. Moreover,the protuberances may be formed by any channel surface although formingthe protuberances on the surface opposite the heat generating devices(i.e., opposite the mounting surface) increases the total surface areaproximate the heat generating device that is in contact with thecoolant. Furthermore, both the cover and the body member may formprotuberances and, in some embodiments, the cover member may form partor all of the cavity 166.

[0204] In addition, while the protuberances 290 are illustrated as beingequi-spaced, equi-spacing is not required and, in fact, it may beadvantageous to provide protuberances that cause a greater amount ofturbulence at the outlet end of the channel than at the inlet end as thecoolant at the outlet end could be slightly warmer and hence couldgenerate more problematic vapor bubbles.

[0205] Moreover, more than one divider may be provided in a cavity. Inthis regard, referring to FIG. 8, another inventive embodiment 160 b ofthe body member is illustrated. In FIG. 8 components similar tocomponents described above are identified by the same number followed bya “b” qualifier. In FIG. 8 cavity 166 b is twice as wide as the cavity166 in FIG. 6. Here, to ensure sufficient turbulence to eliminatestagnant gas pockets from the cavity surface, three separate dividermembers 271, 273 and 275 are provided that equally divide cavity 166 balong its width. In addition, separate inlet passageways 251, 253, 255and 257 are provided that open from inlet chamber 192 c into eachseparate channel within cavity 166 b and separate lines of protuberances261, 263, 265 and 267 are formed within the separate channels. Thus, theprotuberance concept has application in wider sink assemblies alsoalthough it is particularly advantageous in long sink assemblies for thereasons described above.

[0206] In addition, while the sinks are described as being substantiallyvertically aligned and the channels as being parallel to the moundingsurfaces, in some embodiments the sinks may be a few degrees (e.g.,10-15) from vertical and the channels may not be completely parallel tomounting surfaces. Furthermore, referring again to FIG. 17, terminals455 and 457 may not be included in some embodiments while in otherembodiments vias 692 and 694 may provide the DC linking functionalityalone. Moreover, while embodiments are described above where switchingdevice modules configure each of an inverter sub-assembly and arectifier sub-assembly, other embodiments are contemplated where themodules may configure only a rectifier or only an inverter assembly.

[0207] In addition, other embodiments are contemplated including two ormore vertically aligned liquid cooled sinks combined with a laminatedbus bar where the laminated bar links to power switching devices alongonly vertical straight bar edges. For instance, one additionalembodiment is illustrated in FIG. 19 where sinks 502 and 503 withmodules 368, 370, 372, 374, 420, 422, 424, and 426 mounted thereto arevertically end aligned with switching devices linked to one straightvertical linking edge of bus bar 517.

[0208] To apprise the public of the scope of this invention, thefollowing claims are made:

What is claimed is:
 1. An apparatus for linking together power switchingdevices having intra-converter connection terminals to form a powerconversion assembly, the apparatus comprising: a planar bus barincluding positive and negative DC bus layers and insulating layers thatinsulate each of the DC bus layers, the bar also including at least afirst external insulating layer that forms a first external surface ofthe bar, the bar also forming at least first and second linking edges;and first and second pluralities of linkages formed along the first andsecond linking edges, respectively, each linkage linked to one of thepositive and negative DC bus layers and configured to be linkable to atleast one of the power switching device intra-converter connectionterminals.
 2. The apparatus of claim 1 wherein each of the linkages is alinking tab.
 3. The apparatus of claim 1 wherein first and second edgesof the bus bar face in opposite directions.
 4. The apparatus of claim 3wherein the bus bar is substantially rectilinear.
 5. The apparatus ofclaim 3 wherein the first and second edges are straight and wherein thefirst plurality of linkages are aligned along the first straight edgeand the second plurality of linkages are aligned along the secondstraight edge.
 6. The apparatus of claim 5 wherein the first and secondlinking edges are vertically aligned.
 7. The apparatus of claim 1further including first and second external linking vias open to thepositive and negative DC bus layers, respectively.
 8. The apparatus ofclaim 7 also for linking a plurality of capacitors to the switchingdevices wherein the external linking vias open through the fist externalinsulating layer and wherein the laminated bar further includes a secondexternal insulating layer on a side opposite the first externalinsulating layer and forms a plurality of vias opening through secondexternal insulating layer to the positive and negative DC bus layers,the capacitors linkable through the plurality of vias to the DC buslayers.
 9. The apparatus of claim 7 further including positive andnegative DC connection terminals that extend through the first andsecond vias and are linked to the positive and negative DC bus layers,distal ends of the DC connection terminals exposed and connectable to atleast one of a DC source and a DC load.
 10. The apparatus of claim 1 forlinking at least first and second bridge assemblies together with thecapacitors to form a conversion device and, wherein, each of thelinkages in the first plurality is linked to at least one of theintra-converter connection terminals of the first bridge assembly andeach of the linkages in the second plurality is linked to at least oneof the intra-converter connection terminals of the second bridgeassembly.
 11. A three phase electronic converter assembly comprising: atleast a first heat sink member having a mounting surface; first andsecond X phase converter bridge assemblies, each bridge assemblyincluding a plurality of power switching devices, the first bridgeassembly forming first through Xth external linkage terminals and thesecond bridge assembly forming (X+1)th through 2Xth external linkageterminals, each linkage terminal linkable to one phase of at least oneof an X phase source and an X phase load, the switching devices mountedto the mounting surface of the at least first sink member; a pluralityof capacitors; and a bus bar including a positive DC bus, a negative DCbus and a plurality of insulating layers that insulate the positive andnegative DC buses and form an external insulating layer, the linkageassembly linking the plurality of capacitors and each of the bridgeassemblies between the positive and negative DC buses, the bar formingfirst and second external linking vias that open to the positive andnegative DC buses, respectively.
 12. The apparatus of claim 11 furtherincluding a positive DC bus connection terminal linked to the positiveDC bus and having a distal end extending through the first via andexposed for external connection and a negative DC connection terminallinked to the negative DC bus and having a distal end extending throughthe second via and exposed for external connection.
 13. The apparatus ofclaim 12 wherein the bus bar is planar proximate the first and secondvias and wherein each of the positive and negative connection terminalsextend substantially perpendicularly to the bus bar plane proximate thevias.
 14. The apparatus of claim 13 including a second sink memberhaving a mounting surface and, wherein, the first bridge assembly ismounted to the mounting surface of the first sink member and the secondbridge assembly is mounted to the mounting surface of the second sinkmember.
 15. The apparatus of claim 14 further including a bracket memberrigidly linked to and between the first and second sink members, theplurality of capacitors mounted to the bracket member substantiallybetween the first and second sink members.
 16. The apparatus of claim 15further including a controller for controlling each of the first andsecond bridge assemblies to operate as at least one of a rectifier andan inverter.
 17. The apparatus of claim 15 wherein the first bridgeassembly includes at least first and second three phase converterbridges and the second bridge assembly includes at least first andsecond three phase converter bridges.
 18. The apparatus of claim 11wherein X is
 3. 19. The apparatus of claim 18 wherein the first threephase converter bridge assembly includes power switching devices thatform at least first and second three phase bridges and the second threephase converter bridge assembly includes power switching devices thatform at least first and second three phase bridges, each of the threephase bridges including three pairs of switching devices, each of theswitching device pairs including an upper switching device and a lowerswitching device, each device including intra-converter connectionterminals and inter-converter connection terminals, the linkage assemblylinking the intra-converter connection terminals of each of the upperdevices to the positive DC bus and linking the intra-converterconnection terminals of each of the lower switching devices to thenegative DC bus, the inter-converter connection terminals forming thefirst through third external linkage terminals of the first bridgeassembly and forming the fourth through sixth external linkage terminalsof the second bridge assembly.
 20. The apparatus of claim 11 wherein thefirst bridge assembly includes at least first and second three phaseconverter bridges and the second bridge assembly includes at least firstand second three phase converter bridges.
 21. The apparatus of claim 9wherein the sink member is a liquid cooled heat sink.
 22. A three phaseelectronic converter assembly comprising: a first heat sink memberhaving a mounting surface; a second heat sink member having a mountingsurface; first and second X phase converter bridge assemblies, eachbridge assembly including a plurality of power switching devices, thefirst bridge assembly forming first through Xth external linkageterminals and the second bridge assembly forming (X+1)th through 2Xthexternal linkage terminals, each linkage terminal linkable to one phaseof at least one of an X phase source and an X phase load, the firstassembly switching devices mounted to the first sink member mountingsurface and the second assembly switching devices mounted to the secondsink member mounting surface; a plurality of capacitors; a bus barincluding a positive DC bus, a negative DC bus and a plurality ofinsulating layers that insulate the positive and negative DC buses andform an external insulating layer, the linkage assembly linking theplurality of capacitors and each of the bridge assemblies between thepositive and negative DC buses, the external insulating layer formingfirst and second vias that open to the positive and negative DC buses,respectively.
 23. The apparatus of claim 22 further including a positiveDC bus connection terminal linked to the positive DC bus and having adistal end extending through the first via and exposed for externalconnection and a negative DC connection terminal linked to the negativeDC bus and having a distal end extending through the second via andexposed for external connection.
 24. The apparatus of claim 23 whereinthe bus bar is planar proximate the first and second vias and whereineach of the positive and negative connection terminals extendsubstantially perpendicularly to the bus bar plane proximate the vias.